>The new site's map thread feature does not work quite the same as the previous site. In the previous site there were two Map Thread buttons. One would show all posts from the root/original post (like the current site does). And the second Map button would only expand the thread and show posts from the post-branch currently being viewed only. This second one is more useful imo. It allows a user to find a post in a branch and then expand from that point to find the other posts related to that section of a discussion.

In Settings, in the list of checkboxes, you may check "Enable "View all messages from this thread" from the current message".