How to create a credit memo and apply to a multi line Invoice

I want to create an invoice (with multiple lines) and a Credit memo (to be applied on the same invoice) in the same FBDI file. Do i need to split the credit memo and apply individually to each invoice line (LINE & TAX)? Or can i create a single Credit memo line and apply it to the entire invoice?

Business would like to create just 1 line of credit to be applied against the entire invoice amount. So far I'm getting this error in the FBDI file that I'm working with.