You can sort discussion lists, whether All Discussions or those for any individual category, by using the sorting options in the drop-down menu at top of a given list view…
The four options are a bit cryptic by the labels alone, but here are what they do:
- Latest (default) sorts discussions by the the latest thread replies.
- Top sorts discussions having the most reply activity, regardless of whether it’s pinned or not.
- Newest sorts discussions by post date of the initial thread post (i.e. disregarding any reply posts).
- Oldest sorts discussions by post date of the oldest thread post (i.e. opposite of Newest).