Require to have this validation as below:
Step 1 – Tools > Customization Center.
Step 2 – Once Click Customization Center below screen will prompt > Double Click QnE Optimum.
Step 3 – Expand Validation > Expand Rules
Step 4 – Look For QnEBS.BO.Sales.CashSales and QnEBS.BO.Sales.CashSalesDetails.
Note: Expand QnEBS.BO.Sales.CashSales.
Step 5 – Clone CASHSALES.DEBTOR.REQUIRED
Step 6 – Fill in as below. (To Control Cash Sales must be transfer from , but can transfer from any document)
If want to control Cash Sales compulsory Transfer from Delivery Order
Criteria Change as below: