Currently there is only the ability to filter on location fields with set/not set and contains/doesn't contain. We often look to group and filter items by state and zip code, as well as county which currently isn't available at all.

Currently we use dashboard widgets with a contains filter by zip code or state, or multiple filtered views to get around the inability to group by. The only way to get the county is for us to manually add another custom dropdown field and add in the county (which is not only an extra step, but more opportunity for error).