[Zubersoft]

I believe if you filter on multiple collections, it does an OR type comparison. It will show any songs in any of the selected collections. The exclude filter likewise excludes any song in any of the selected collections. You can't currently do more complex searches like you are describing - i.e. show me songs only in one collection and not another, or show me songs belonging to multiple collections. In order to support those kinds of comparisons, I would probably have to support a more open ended search language where you could enter a query with logical operators and comparisons of specific field values.