I have found a way to search multiple collections. It will do until Logos implements a quicker way to search more than 1 collection.
I have created a Collection called "#Collection Search". I included the hash mark so it will show up at the top of the collections list in collections window and search window. I created a shortcut to this collection.
When I want to do a search on more than one collection I initiate the search as usual then click on the "#Collection Search" shortcut and then just add/delete entries to/from the "+ Plus these resources" area. I then select the "#Collection Search" collection in the search dialogue and it searches whatever collections I have set up. Hope this idea helps someone else!
