Customised sidebar in Gitlab Wiki with nested dropdown menus?


I am building a Wiki for a repo. I would like to be able to customise the sidebar, but still enable the dropdown menus of nested pages that is there when the default sidebar is used. So far I have only been able to write a file that has the nested structure via indentation, but not with dropdown menus.

I am using am using GitLab community edition 15.10.2, through my institute’s account.

Any hints to that topic? Thank you!