Yes, I think you just found that threat as well. It would be hugely powerful for tags or other attributes from Focus to be able to use AND logic:
Some Focus items do work that way. You just cannot decide AND or OR for Roon Tags.
Foobar was great. But I don’t miss it in the sense that it’s still there; I still put all the Foobar-relevant metadata when I rip CDs or buy hi res files; but I only launch it for admin purposes at this point. But the filter concept – the ability to quickly drill using the Boolean logic in the form of selectable items in columns is hugely powerful. It actually is not that different from the Smart Playlist idea, except that it can use custom tags which is great since we all have our own ideas of navigating our collections.
Yes, we could slice and dice however we wanted. I will add, though, that since these characterizations are object-by-object: track by track, artist by artist, etc., this data would best be embedded in the files. Spending weekend after weekend applying these tags shouldn’t be lost if Roon goes away (or changes) for any reason: I’d want to be able to take that data and use it again within Foobar, J River, or whatever.
EDIT: I posted what I think may be a potential workaround for the Boolean logic issue: