Threaded comments are built into WordPress and therefore BuddyPress but not in the forum section currently.
I’m not aware of this being on the roadmap but I did find a thread around the similar topic that may be of use to you.
https://buddypress.org/community/groups/creating-extending/forum/topic/threaded-forum-posts/
Thanks Tammie. I did see that thread earlier but it isn’t clear to me whether the conversation was more around threaded comments rather than forum posts.
I was hoping to do this too. Is this something that will be easier to accomplish the the component api?
I too would like to have this. Forums typically don’t allow threaded posts – that was an invention of comment threads. I would consider threaded forum posts to be more of a “discussion group” than a forum. WebCT (now called Blackboard) uses “discussion groups” and it’s quite useful in that context.
Ideally this could be a enabled/disabled feature under buddypress’s settings for group forums. I don’t see a need for threaded forums in a global forums context.