Theoretically this should be possible with a KML file. You can draw the single areas and by click on them you would then zoom in and see the locations in the area.
Look at this example:
kml-samples.googlecode.com/svn%3D/trunk/...ns.Google_Campus.kml
You can click on the polygon and the map will zoom in. You can create a similar KML file in google earth and then upload it in Hotspots for a specific category. Then it will be drawn on the map. (when you test this make sure that you are on a live domain and not localhost, because on localhost this cannot work as we need to provide the url to the KML file and it should be accessible by google).
The KML import is part of the pro version.
Regards,
Daniel