Identify Groups of Owners within the Owner field on the Cockpit

Under the Owner filter, would like to be able to identify groups of owners. 

For example, the manager of the AMER CSMs could look at the Cockpit and show all the CTAs owned by the AMER team of CSMs.

Using the filter for this task is not realistic.

Wonder how companies with groups of CSMs are managing the teams of CSMs ?  we have reports and dashboards created, but would be nice to view in the Cockpit in an easy fashion as well.
How are your groups represented in Salesforce?  Through Salesforce's Role Hierarchy?
we do use a role hierarchy but have not defined any SFDC groups