How to get Worldmap Panel data in?

Our WatchGuard firewall is feeding its syslog data into Graylog. I have two extractors to pull out src and dst countries which get added to the record so each item I would like to track. I can query a subset and quick-view the data in Graylog. I’ve been trying to get Worldmap to work with the data coming out but I cannot figure out how to get the field geo_country into Worldmap to work.

Is it possible to use WorldMap for this?

Not 100% sure how I got it working but I got it working.

I’ve updated the documentation and added some fields for mapping between the metric query and the location data. Hope that helps explain how it works: