Due or Flagged or a given context in a single perspective?

Hi

I currently have a Daily Dashboard perspective that includes items that are Due or Flagged, and that works great. However I’ve started to use a ‘waiting for’ context to signify those things where I’m waiting for someone to reply back via email etc. What’s the best way to add the ‘waiting for’ context to my Daily dashboard, obviously adding the context as a focus just filters for that context and therefore doesn’t give me the desired result. In essence I’m looking for a way to create a perspective that shows my flagged, due and ‘waiting for’ context items in a single place.
Thanks