Online Documentation for SQL Administrator for SQL Server
Defining server role membership
The Member of server roles tab of Server role Editor allows you to define role membership, i.e. to select the built-in server role(s) the current role will be a member of. The selected roles determine the tasks that can be performed through the current role.
This tab is available on creating a new server role only.
To select a role, you need to move it from the Available Server Roles list to the Selected Server Roles list. Use the buttons or drag-and-drop operations to move the roles from one list to another.