From ask the staff re new replies

[Lizzie]

The OP is saying, when you click on "show new replies to your post" up at the top in the User Info box after logging in, you will see new replies even to very old threads that you once posted in a million years ago. The OP is asking if there's any way to filter out those old threads from the "show new replies to your post" clickie.

The answer - is no, there aren't any filters on the GDB for that. However, what you -can- do is click on "Mark as read" on the upper right of the GDB, and it'll "untarget" all posts to that minute, and remove them from your viewing. And after that, you can "show new posts since last visit" instead of "new replies to your post" and you'll start seeing new posts, no matter who they're replied to, in chronological order of the time of the most recent post.