Just an update on this feature request. We currently allow you to filter by 'City' in Real User Monitoring, using the filter bar at the top of the page. You can filter across all tabs in RUM (except the live tab), to view data that conforms to the filter/s.
I would recommend using city filters on the performance tab in RUM, to understand the median, average, P90 and P99 load time for a particular city. You can also filter on state level, using the state filter.
Note, filters are generated based on the data that you've sent to Raygun. Therefore, you won't be able to filter on a particular city or state if you haven't had any user sessions from that area.
This is not to say that we won't update the Geo tab in RUM to provide city-level drill down in future. However, given this feature isn't on the immediate roadmap, I thought I would share this workaround.
Hopefully this helps.
Product Manager, Raygun