Hi
You will be able to derive the planning level on line item BSEG-FDLEV by user exit, have implemented BTE1120, or you could probably use Substitution rule. The logic may be to look at REGUH table to search the payment method from the document number then to determine the required planning level.
"Define levels of payment request" IMG is relevant only where you use the payment request (i.e. TRM, IHC) to assign a specific planning level for open Payment request.
If line items have the correct planning level on the line item, you should be able to see that in FF7A/B. In cash position report, you would use the summary level based on the GL account structure (a range of 10 accounts for each house bank), however, this would not be easily achievable.
cheers
taro