I can’t seem to figure out how to do this in liftoff.
The best search and find method that I have for communities is to create a new post and I can search through the communities on an instance there.
However I’m not sure how else to search for communities, it just go directly to one, as the search function isn’t to helpful right now.
If you’re using Jerboa or Voyager, there should be links to the ones you’re subscribed to in the menus where you decide the sorting of your feed, like this: