I believe that this feature can be enabled to be automatic for any logged on member.
I frequent quite a few forums and many use the exact same forum software and all you have to do is to click on any thread and it will automatically take you to the next new message for you in that thread.
If you look next to a topic with a post that you haven't read yet you'll see this image:
. Click it and it will take to the first post that you haven't read in that topic.