I don't know if you can get as fine-grained as "posts relating to programming" or "people you haven't interacted with in X days" but you can add people to "List

I don't know if you can get as fine-grained as "posts relating to programming" or "people you haven't interacted with in X days" but you can add people to "Lists" and then switch your wall view between those lists. One person can be in many lists.