Flexible Hierarchies enables you to add subsections (sections in sections), to your help center knowledge base to create more levels in your hierarchy, up to six levels deep.
By default, the help center category page lists all sections in the category and all articles in each section in the category. When you add subsections to a section, the category page does not list subsections in the section by default, but instead the section with subsections appears as "empty" on the category page.
You can modify your template to change that behavior by using the helper
section.sections to loop through to present the subsections in a section.
You can only show the direct subsections of a section. You cannot show multiple levels of subsections.
Showing subsections in both the category and section page
For the section page, the template shows a preview of the articles directly under it, and the list of sections' subsections with a preview of their articles
For the category page, for each section, the template shows a preview of the articles within, and the list of its subsections
Showing categories and sections as blocks
For the section page, the template shows all of the section's immediate subsections as blocks, and all the articles directly below
For the category page, template shows all immediate sections as blocks
Showing subsections in the standard Copenhagen theme
Our own implementation of subsections in the Copenhagen standard theme groups them at the top of the section page while showing the article list below.
Here’s a link to the section page template.