Vega / vega-lite multi-level / hierachy axes

Question

i have seen view composition techniques like facets etc. however i am struggling to create a plot that features multiple view cells / subplots for different combinations of dimensions/groups as seen in the image for the x axis. it should be possible to not only do this for year-month-day but also for something as "country, year" and then plotting e.g. some continuous x vs. y scatter as subplot within individual cell for specific country & year.

could you provide an example json for auch a plot, so that i can have multiple groups applied for both x & y axis?

please see following vega spec for what I've tried already. I would like to add a graph on top of it, the colored boxes should be the scales.

https://vega.github.io/editor/#/url/vega/N4KABGBEAkDODGALApgWwIaQFxUQFzwAdYsB6UgN2QHN0A6agSz0QFcAjOxge1IRQyUa6SgBY6AK1jcAdpAA04KAHdGAExbYwogAw7FESCkbV8WgMx6DUQujVrGM6lv0glkWCZnoANrC0A2koQwFDeqMhakGC29o7O8lAUvqyROK4QmVDsjmpawJCOhKx4UQBO6E6RiZCoji41GAAeWgCM+lCweMiEbQC+YH3WIWHoEeXcrDJ5Nck+qVoAZr6wyDU50-mFMsWlOJBIyPAA1uzcLQNDwWChkOFpSchleIzwvgpJKQ-LfmvZuVsiiUoocTmcLoMlABdRTuNToPCYHBBLKgLKGe5RPBlZDVa6GOapfzI-GZArqKIAQQ+kFsOJkezAMlYPh8sy+Liu6LJhTy+wAQjS6cgGVSaYSHq0udybryogBhIXoemMyDU9nzB46aXc8l8qAAESVKoV4o5OClw3ReqiAFFjSLVYqNQsLX1STDSZBsZVYItuGVUIFSSEQ5lvQBPQgPDw+l6LCMKMOGY7IRP7ClW7m05WOgDSaaiwtFYZ11uTUDwUZjdJeL1kSZl4cWjGQPn1kAljabNjsDicW081G8PiiMT78UgZezZUmmxwBSHI4mUzy0-RHkYAC8HgFF153vsqM9Xr4wAB+MDGUx4MA4VQaRBTxL74eHx4nt4+C9gB8sO9XsgJhmH0UKlh61zuhAnruAgvjIMSYAomSXqYvs8DcD4AbdlkkbRlEAb9u8WZQBUVSDoc4zoQiNABhGABMOhTpB0KwoYGBlMciHIaG2ZVvh+w4vApQkZAiyzkGC6QPCiJYjikTrpAIoYWoDxojKSkMk8+QVmJjCshR8Egph2E1C2bYdhSUEyuuhisIQMlqbp6ayku76dk8Lxfj+MmsKgdBNDoAHXvgAC0vn+RGTG2eGDGDgeo5Hp5p7fpeEUBa0wVATe4UIn5dARq0z66S0UluYlH5eWeaV5ZFQU4OlgVQDFhhNPR8VvhVHmftVEDpYVAGNUV1nciNmRjdZYHukAA

Answer 1

There are a number of faceting examples in the Vega-Lite gallery.