If you couldn't find it from the community search bar it's likely mean it doesn't get federated yet(as in no one in this instance look for that community). To help with this, if you're using browser, you can type in the link of the community(if you've found it), like:

https://monyet.cc/c/CommunityName@Instance.Name

Example: https://monyet.cc/c/woodworking@lemmy.ca

You might get error at first, but once this instance done fetching the community then post will start appearing. The same reason why you can find it in Lemmy.world and lemmy.ml it's because there's people already looking for this community prior(or someone use bot to fetch community), so it's already linked.

For browsing community in the lemmyverse, do try this community browser.