We have requirement to club events as different Invoice lines for the invoice created on Contract

We are using Amount based invoicing method. So, on the contract and a particular contract line billing events will be created with the billing amount to create a sales invoice.

There will be multiple items on a Delivery note. For each of them, there will be a separate Billing event created based on the item and amount for that line of the delivery note. And there will be multiple such delivery notes for a period.

Our requirement is that all these billing events that are created for each line on the delivery note, should generate separate invoice lines and all these invoice lines should be clubbed under an Invoice.