You build your own lists. On a profile page there's a "tags" field, so you can tag people with like #fedsocweb or #saunaclub and then to post to them you "mention" the hash tag and it's like writing all the nicks at once.
So you can choose yourself who to include. Reasonably these lists could be shared and you could mention someone else's list.
So you can choose yourself who to include. Reasonably these lists could be shared and you could mention someone else's list.