How to set geolocation field value from BR?

I would like to set the "geolocation" field values using the "Centroid" coordinates from a "geofield" field, as illustrated below:

Centroid lat/lon tags work as designed, but I don't know how to store this data in the geolocation type field. Could you please explain/document how this is done?

More generic: how does one populate any field of a "complex" type using the BR? Under "complex" i mean a field that isn't just a single value string or number but has an internal structure.