How to group pick slip by Cost Group (pick slip grouping rules)

We are working on EBS Oracle Applications : 12.2.8 on premise implementation. The customer requirement is to have pick slips grouped according to Cost Groups. In WMS Stock is put away into specific Cost Group. In Order management Sales orders are created with DFF for Cost group and Picking rules reference the set cost group in the order to pick stock that belongs to that cost group from the on hand inventory.  How do we make pick slip grouping rules or pick slip grouping by Cost Group.