Assignment between Sub Order & Superior Order is at header level, not at operation level.
Also, functionality of having Sub Order & Superior Order is to have the relationships between the orders which have been created for hierarchical technical objects. IW40 is Multi level list that may show the superior order, but not IW37N / IW37 / IW49 / IW49N.
As mentioned before, you have to develop a custom report.
Hope, cutting the operations in one order & pasting that in another is being done manually. Also, you can see both Superior order & Sub order in IW49N.
