I do not believe you can do that. However, you can “Watch” a topic, which then you can click your Unread/Inbox icon (second from the left) on the top menu bar. Then, you can select to view Watched topics only. They will show in this filter list if there are any new replies since you last visited them.
I know it’s not as straightforward as FW was, but this should work for now. Basically, it’ll give you a “favorites” list of threads that you can quickly see if there are any updates on, across all forums.