Highcharts Line Chart Drill down not working properly

Question

In my application I have a Line chart showing employee head count variation in several departments over several years. Then when I click on a one data series(Ex: Department A) I need to show a drill down of that selected department. I have added the drill dwon code and drill down data to the chart definition. Seems it's not working properly. I couldn't find what's wrong here. Is there a workaround for this one. Sample code is as following.

http://jsfiddle.net/yasirunilan/qja2s3rb/9/

 var chart = new Highcharts.Chart({
    chart: {
      renderTo: "container-main-bar",
      type: "line"
    },
    title: {
      text: null
    },
    series: [{
      "name": "Department A",
      "data": [{
          "name": "Month1",
          "y": 27,
          "drilldown": "levelA2"
        },
        {
          "name": "Month2",
          "y": 24,
          "drilldown": "levelA2"
        },
        {
          "name": "Month3",
          "y": 22,
          "drilldown": "levelA2"
        },
        {
          "name": "Month4",
          "y": 26,
          "drilldown": "levelA2"
        },
        {
          "name": "Month5",
          "y": 21,
          "drilldown": "levelA2"
        },
        {
          "name": "Month6",
          "y": 22,
          "drilldown": "levelA2"
        },
        {
          "name": "Month7",
          "y": 23,
          "drilldown": "levelA2"
        },
        {
          "name": "Month8",
          "y": 24,
          "drilldown": "levelA2"
        },
        {
          "name": "Month9",
          "y": 21,
          "drilldown": "levelA2"
        },
        {
          "name": "Month10",
          "y": 20,
          "drilldown": "levelA2"
        },
        {
          "name": "Month11",
          "y": 22,
          "drilldown": "levelA2"
        },
        {
          "name": "Month12",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month13",
          "y": 23,
          "drilldown": "levelA2"
        },
        {
          "name": "Month14",
          "y": 24,
          "drilldown": "levelA2"
        },
        {
          "name": "Month15",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month16",
          "y": 26,
          "drilldown": "levelA2"
        },
        {
          "name": "Month17",
          "y": 24,
          "drilldown": "levelA2"
        },
        {
          "name": "Month18",
          "y": 23,
          "drilldown": "levelA2"
        },
        {
          "name": "Month19",
          "y": 23,
          "drilldown": "levelA2"
        },
        {
          "name": "Month20",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month21",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month22",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month23",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month24",
          "y": 25,
          "drilldown": "levelA2"
        }
      ],
      "drilldown": {
        "series": [{
          "name": 'Headcount',
          "id": 'levelA2',
          "data": [{
              "name": "Month1",
              "y": 10,
            },
            {
              "name": "Month2",
              "y": 12,
            },
            {
              "name": "Month3",
              "y": 11,
            },
            {
              "name": "Month4",
              "y": 10,
            },
            {
              "name": "Month5",
              "y": 9,
            },
            {
              "name": "Month6",
              "y": 8,
            },
            {
              "name": "Month7",
              "y": 10,
            },
            {
              "name": "Month8",
              "y": 12,
            },
            {
              "name": "Month9",
              "y": 11,
            },
            {
              "name": "Month10",
              "y": 13,
            },
            {
              "name": "Month11",
              "y": 14,
            },
            {
              "name": "Month12",
              "y": 10,
            },
            {
              "name": "Month13",
              "y": 9,
            },
            {
              "name": "Month14",
              "y": 8,
            },
            {
              "name": "Month15",
              "y": 11,
            },
            {
              "name": "Month16",
              "y": 10,
            },
            {
              "name": "Month17",
              "y": 9,
            },
            {
              "name": "Month18",
              "y": 10,
            },
            {
              "name": "Month19",
              "y": 11,
            },
            {
              "name": "Month20",
              "y": 12,
            },
            {
              "name": "Month21",
              "y": 13,
            },
            {
              "name": "Month22",
              "y": 10,
            },
            {
              "name": "Month23",
              "y": 11,
            },
            {
              "name": "Month24",
              "y": 12,
            }
          ]
        }]
      }
    }, ],
    xAxis: {
      categories: [{
          "name": "2013",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        },
        {
          "name": "2014",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        },
        {
          "name": "2015",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        },
        {
          "name": "2016",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        },
        {
          "name": "2017",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        },
        {
          "name": "2018",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        }
      ]
    },
    yAxis: [{ // Primary yAxis
      title: {
        text: 'No. of Employees'
      },
    }],
  });

Answer 1

first you have to add drilldown.js in your HTML

<script src="https://code.highcharts.com/modules/drilldown.js"></script>

and drilldown object is wrongly entered in the input JSON object. it should come out of series. below is the correct format. Please have a look in the code snippet.

$(function() {
  var chart = new Highcharts.Chart({
    chart: {
      renderTo: "container-main-bar",
      type: "line"
    },
    title: {
      text: null
    },
    series: [{
      "name": "Department A",
      "data": [{
          "name": "Month1",
          "y": 27,
          "drilldown": "levelA2"
        },
        {
          "name": "Month2",
          "y": 24,
          "drilldown": "levelA2"
        },
        {
          "name": "Month3",
          "y": 22,
          "drilldown": "levelA2"
        },
        {
          "name": "Month4",
          "y": 26,
          "drilldown": "levelA2"
        },
        {
          "name": "Month5",
          "y": 21,
          "drilldown": "levelA2"
        },
        {
          "name": "Month6",
          "y": 22,
          "drilldown": "levelA2"
        },
        {
          "name": "Month7",
          "y": 23,
          "drilldown": "levelA2"
        },
        {
          "name": "Month8",
          "y": 24,
          "drilldown": "levelA2"
        },
        {
          "name": "Month9",
          "y": 21,
          "drilldown": "levelA2"
        },
        {
          "name": "Month10",
          "y": 20,
          "drilldown": "levelA2"
        },
        {
          "name": "Month11",
          "y": 22,
          "drilldown": "levelA2"
        },
        {
          "name": "Month12",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month13",
          "y": 23,
          "drilldown": "levelA2"
        },
        {
          "name": "Month14",
          "y": 24,
          "drilldown": "levelA2"
        },
        {
          "name": "Month15",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month16",
          "y": 26,
          "drilldown": "levelA2"
        },
        {
          "name": "Month17",
          "y": 24,
          "drilldown": "levelA2"
        },
        {
          "name": "Month18",
          "y": 23,
          "drilldown": "levelA2"
        },
        {
          "name": "Month19",
          "y": 23,
          "drilldown": "levelA2"
        },
        {
          "name": "Month20",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month21",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month22",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month23",
          "y": 25,
          "drilldown": "levelA2"
        },
        {
          "name": "Month24",
          "y": 25,
          "drilldown": "levelA2"
        }
      ]
 } ],
 
      "drilldown": {
        "series": [{
          "name": 'Headcount',
          "id": 'levelA2',
          "data": [{
              "name": "Month1",
              "y": 10,
            },
            {
              "name": "Month2",
              "y": 12,
            },
            {
              "name": "Month3",
              "y": 11,
            },
            {
              "name": "Month4",
              "y": 10,
            },
            {
              "name": "Month5",
              "y": 9,
            },
            {
              "name": "Month6",
              "y": 8,
            },
            {
              "name": "Month7",
              "y": 10,
            },
            {
              "name": "Month8",
              "y": 12,
            },
            {
              "name": "Month9",
              "y": 11,
            },
            {
              "name": "Month10",
              "y": 13,
            },
            {
              "name": "Month11",
              "y": 14,
            },
            {
              "name": "Month12",
              "y": 10,
            },
            {
              "name": "Month13",
              "y": 9,
            },
            {
              "name": "Month14",
              "y": 8,
            },
            {
              "name": "Month15",
              "y": 11,
            },
            {
              "name": "Month16",
              "y": 10,
            },
            {
              "name": "Month17",
              "y": 9,
            },
            {
              "name": "Month18",
              "y": 10,
            },
            {
              "name": "Month19",
              "y": 11,
            },
            {
              "name": "Month20",
              "y": 12,
            },
            {
              "name": "Month21",
              "y": 13,
            },
            {
              "name": "Month22",
              "y": 10,
            },
            {
              "name": "Month23",
              "y": 11,
            },
            {
              "name": "Month24",
              "y": 12,
            }
          ]
        }]
      },
    
    xAxis: {
      categories: [{
          "name": "2013",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        },
        {
          "name": "2014",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        },
        {
          "name": "2015",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        },
        {
          "name": "2016",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        },
        {
          "name": "2017",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        },
        {
          "name": "2018",
          "categories": ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
        }
      ]
    },
    yAxis: [{ // Primary yAxis
      title: {
        text: 'No. of Employees'
      },
    }],
  });
});

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<script src="http://code.highcharts.com/highcharts.js"></script>
<script src="https://code.highcharts.com/modules/drilldown.js"></script>
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