Openlayers views , center map to each geofield
Go to /admin/structure/openlayers/maps
Choose the map you are using to display your geofield on the user
Select the behaviors tab
Check off Zoom to Layer
Select geofield_formatter
Enter your zoom level




Note: If I misunderstood your question, and you were actually referring to centering on the markers on your view that compiled all of the users, then just select your view name in the 'Zoom to Layer'.