At the top of the main page, you should see an icon or button that says: VIEW NEW CONTENT. This will pull up all the posts since you last read the forum AND closed the forum by finding and clicking the MARK COMMUNITY READ button at the bottom of the screen.
Additionally, there are dots/stars/bullet points to the left of the topics. If you will double click on these bullet points, you will be taken to the most recent post.
Haven't ever paid attention to the "view new content" button until now. Just went to it, and it looks to be easier than going from forum to forum.
EDIT: Added a quote of the previous post since this is the start of a new page.