This is typically handled by flairs on game specific subreddits pretty handily. I think they are supported on Feddiverse.

We are still a small community here in the Fediverse. I don't mind any talk about Baldur's Gate 3 posted. I think we have a great group of people here who love playing the game. Maybe using [Build Class] in the title will help sort the subtopics.

But I believe anyone could start a community for builds or anything else.

For topics which generate a lot of posts, something like a separate BG3Builds community might be sensible. That's what they're doing on reddit although they get a lot more traffic than here.

I'm pretty new to Lemmy, if anyone has a good way to do this what works with our content, please let me know. I think it will be more and more necessary as our numbers grow.