Please, pretty please, add a Filter button to the Notifications panel, in the group area, and allow us to select from our list of groups?

Maybe upt at the top or something?

I'm in plenty of groups that send notifications of events all the time, and I don't want to leave the groups, but I really don't need the 20 notifications I missed over the weekend.... I want to "Delete All" but not all notifications from ALL groups, just from certain ones.

Filter solves it all.