Yes, I haven’t tried it myself but my understanding is that kbin is exactly that. What kbin calls a “magazine” maps directly with Lemmy communities/subs and a kbin user can subscribe to a Lemmy sub via the same process they would use to subscribe to a kbin magazine. Kbin microblogging maps directly with Mastodon posts and so a kbin user can follow Mastodon users and their posts the same way they follow fellow kbin user microblogs.