Dynamic Query for a group that shows just the physical servers

I would like to create a dynamic query for a group that will populate our physical servers.  I started creating a custom field but I would rather have the group populated on it's own when a physical server is added.  I cannot find the physical server property anywhere in the database.  I would also like to do this with our virtual servers also.  Create some kind of dynamic query that will add our VMs to a group based off the Hardware field like below -

Thanks