Linking playlist to custom submenuitems?

Hi forum.

In Kodi 16 using the confluence skin I was able to manually create submenuitems in the IncludesHomeMenuItems.xml and then link those to custom playlists.
This was very nice since my kids have their movies in one folder and I have mine in three different folders. In that way I don’t have to be bothered with all the kids movies when scrolling through my movies.

Upgrading to Krypton I want to accomplish the same with the new Estuary default skin. As far as I can read it is possible to create customs submenus. Can you confirm that?
If so, how would I link the custom submenu to my playlists (or folders)

All good ideas would be very much appreciated:-)