I've already asked this question, and awarded points. However, I have since realised that it isn't quite what I requested. The attached solution assumes one master form with two children. What I am looking for is one parent form (S_ContractYears) with one child (Guarantees), and that has a child (S_RevSharePmts), which is a grand-child of S_ContractYears. So S_ContractYears has one or many Guarantees, which in turn has one or many S_RevSharePmt.