How do I search my library by more than one tag?

I've tried searching my library by multiple tags, and it seems to search by title at that point. I've tried putting in commas, backslashes ("\"), and a few other methods. Is this even possible? I put the tags there so that I can progressively narrow my search options for a streamlined and tailored GM interface. If this does exist, please let me know how. If not, I think it should exist.

I don't think that this is possible at the moment. I'll make sure to put the request on the devs' list.