Searching with multiple tags

I’m coming from Evernote and am trying out Devonthink, and am quite impressed. However, I’m having troubles with tags/groups as they exist now. My current setup has an Academic database, under which I have a storage place for papers, as well as notes related to various conferences. All the papers are in a Papers group, and the notes in a Notes group. Everything related to a specific conference has the Conference tag.

However, I can’t find a way to find the intersection of two tags, as it were. I want to find all things tagged with both Conference and Paper (or really powerfully, Conference and NOT Paper). I’ve tried the obvious methods to do this, and none of them have worked. I think this is not an esoteric desire, so making this easier to accomplish would be nice (or alternatively, informing me of the obvious interface element I’m overlooking would also be nice)

Thanks

There are two possibilities right now: Either to select both tags in the Tags view or to use a smart group. But searching for tags is another thing that will be improved rather sooner than later.