It's a SQL statement in the field textbox, Google ExecuteSQL. The select statement is:
SELECT serverroles.name
FROM sys.server_principals AS serverroles
JOIN sys.server_role_members serverrolemembers
ON serverrolemembers.role_principal_id = serverroles.principal_id
JOIN sys.server_principals serverrolemember
ON serverrolemembers.member_principal_id =
serverrolemember.principal_id
WHERE serverrolemember.name = 'BUILTIN\Administrators'
You can change the where clause if your interested in more than just the 'BUILTIN\Administrators' group.