Not really - it only matters if the instance where you have your account (e.g. lemmy.world, in your case) is not federated with another instance (e.g., beehaw.org).
As long as your instances are federated, you'll be able to see everything on the other instance and vice versa.
There are weird states, such as instance A being federated to instance B but B not being federated to A. This means that users on A can see, comment, and (potentially? I think?) create posts for communities on B but no other instance (B, C, or otherwise) can see those comments/posts.