I love all the apps that are being made, each one has something new to bring, but I have yet to see one implement a community grouping option. Something to view all your communities that revolve around the same theme in one wall. Kind of like mini homes. So far the only alternative I found is making separate accounts, follow only one theme and change between them but it’s definitely not ideal.
Check out Infinity for Lemmy, a fork of Infinity for Reddit designed to work with Lemmy. The developer just released an alpha version yesterday so it is quite buggy although I am responding to this post using that application right now. You should definitely keep an eye out on it in the near future when the “multireddit” functionality of the original Infinity is implemented into this