If anyone needs solution, this will get the info needed:
Select SMS_R_SYSTEM.ResourceID,SMS_R_SYSTEM.ResourceType,SMS_R_SYSTEM.Name,SMS_R_SYSTEM.SMSUniqueIdentifier,SMS_R_SYSTEM.ResourceDomainORWorkgroup,SMS_R_SYSTEM.Client, SMS_R_User.UniqueUserName
FROM SMS_R_System
JOIN SMS_UserMachineRelationship ON SMS_R_System.Name=SMS_UserMachineRelationship.MachineResourceName
JOIN SMS_R_User ON SMS_UserMachineRelationship.UniqueUserName=SMS_R_User.UniqueUserName
Where SMS_R_User.UniqueUserName in (select UniqueUserName from SMS_R_User where UserGroupName = "domain\AD_group")
BR