I think it's possible to create those groups in you xml file, just like in this tutorial https://www.odoo.com/documentation/9.0/howtos/backend.html you can add partner catagory (in the "domain" chapter). If you make a group_by with those elements created they should be displayed.
It looks like if you use Selection field for the group, it doesn't work, but if Many2one is used, then it is showing the empty columns.