How to apply a lockbox receipt to child customer's transactions using Customer Hierarchy?

Summary:

Business Scenario: 

Medical service invoices for multiple customers are sent to a single insurance company, which acts as a customer, and are paid by the insurance company via lockbox. We need to apply a lockbox receipt from the insurance company to multiple unrelated customers. Oracle notes suggest that 'Customer Hierarchies and Paying Relationships' could be a solution for this scenario.  

Content (please ensure you mask any confidential information):

Setups completed:

1. Created a customer hierarchy and assign Pay Below relationship

Parent Customer: PCUST

Child Customer1: CCUST1

Child Customer2: CCUST2

Child Customer3: CCUST3

2. Go to Manage Customer Paying Relationship Assignments - and create a pay below assignment - save and close