Maybe I am not understanding the fedivers well enough, but why am I not seeing communities like !flippanarchy@lemmy.dbzer0.com from my europe.pub account?
The instances seem to be federated.
Edit: they are accessible when using a direct link like the one in the first paragraph, but the search function doesn’t seem to work.
If a community isn’t federated yet, you need to put the full name or link into search. After at least one local user has subscribed, it will show up for all.
Simply copy the community name with instance name (e.g. !memes@lemmy.world) or the community link (e.g. https://lemmy.world/c/memes) and put it into the search.