Rails 6 with ancestry gem: show entire tree, from root until the very last subcategory

Question

I'm using the ancestry gem in order to create categories, subcategories, sub-subcategories and so on. Everything is working just fine, I can create a category, then create a subcategory which belongs to this category and then create a sub-subcategory for the subcategory and so on. The only issue I'm having is that I cant figure out how to show all the categories with each full tree from root until the very last subcategory inside a view.

Currently I have the following setup and I'm getting only up to the subcategory:

Inside the controller: @categories = Category.where(ancestry: nil).order('name ASC')

Inside the view :

<% @categories.in_groups_of(3) do |category| %>
  <div class="row">
    <% category.each do |item| %>
      <div class="col-md-4">
        <% if item.present? %>
          <ul>
            <li><%= (item.name) %>
              <%= link_to edit_category_path(item) do %><i class="fas fa-edit"></i><% end %>
              <%= link_to new_subcategory_path(ancestry: item) do %><i class="fas fa-plus-circle"></i><% end %>
              <%= link_to category_path(item), :method => :delete, data: { confirm: "Are you sure?" } do %><i class="far fa-trash-alt"></i><% end %>

              <% unless item.children.empty? %>
                <ul>
                  <% item.children.sort_by(&:name).each do |subcategory| %>
                    <li>
                      <%= subcategory.name %>
                      <%= link_to edit_category_path(subcategory) do %><i class="fas fa-edit"></i><% end %>
                      <%= link_to new_subcategory_path(ancestry: subcategory) do %><i class="fas fa-plus-circle"></i><% end %>
                      <%= link_to category_path(subcategory), :method => :delete, data: { confirm: "Are you sure?" } do %><i class="far fa-trash-alt"></i><% end %>
                    </li>
                  <% end %>
                </ul>
              <% end %>
            </li>
          </ul>
        <% end %>
      </div>
    <% end %>
  </div>
<% end %>

Then I found this solution, which does show the root until the very last subcategory. But I cant really use this solution, since I have a few link_to that I want to show inside the loop(as you can see above). Any ideas how I can make the above solution show the root until the very last subcategory?

@items_tree = Category.all.arrange

def nested_groups(groups)
  s = content_tag(:ul) do
    groups.map do |group, sub_groups|
      content_tag(:li, (group.name + nested_groups(sub_groups)).html_safe)
    end.join.html_safe
  end
end