It would be great if we had the ability to filter by the logged activities "Add to SFDC Campaign", "Change Status in SFDC Campaign", and "Remove from SFDC Campaign", as these filters do not exist when attempting to create a Smart List.
I realize this is very old but I was looking for a way to pull up a list of leads who got removed from an SFDC campaign (because it's not actually part of a flow) and I don't actually see an option to add that as a filter in a Smart List, even though it says "Already Have it"