Submenus for publications

[p-wegmueller]

Dear community,
I would like to set up submenus for my publications page, i.e., similar to http://info.phys.tsinghua.edu.cn/kimkihwan/ I would like to have something like

• publications
  --- academic
  --- policy
  --- working papers

I tried already quite a lot, but did not succeed. I would appreciate guidance on how to do that appropriately, also with corresponding .bib files.
Which changes do I need to make in

• config.yml
• layout.html
• publications.md

Thanks!

Currentyl, my page looks like: https://p-wegmueller.github.io/

[george-gca]

At least the submenu part is already supported in the current template. As for expand on hover, this probably is done via css, but I am not fluent in css. I would recommend checking their page source using the developer tools available in Chrome or Firefox.