Is it something like that?
[Sale Groups:2, 1, 1] @{REPORT ORDER DETAILS:MT.Group,O.Quantity.Sum::{0}:,} >>$1 {REPORT ORDER DETAILS:M.GroupCode,O.Quantity.Sum,O.ExactTotal.Sum:(MT.Group=$1)} >Total:||{REPORT ORDER DETAILS:O.ExactTotal.Sum:(MT.Group=$1)}