Yep, it's like if subreddits were sorted into larger groups of subreddits, like say a megareddit where you can have many subreddits with the same name as other subreddits, but a little bit different.
So instead of going to /r/aww, you would hypothetically go to /r/lemmy.one/aww or /r/beehaw/aww. They can have different sets of rules but you can see and post to both equally.