Importing multiple lines on one AP Bill using Business Event

Hello-

The mission is to use business event to trigger an import scenario subscriber to create AP Bills. The business event will be triggered on a schedule, the source screen is a Generic Inquiry containing fields that is required for an AP Bill creation. 

The bill ref. nbr is auto generating. We want to create bills based on vendor ID. Meaning if each line record in the GI has the same vendor, then they should all be imported under the same vendor in the same bill. 

Currently, my business event is firing, and it is creating a bill. But it is creating one bill per each line on the generic inquiry. I want one bill per vendor. 

This is the import scenario, salesPersonID field on the GI is the field we want to use as vendor on AP Bill.  

I’m open to any suggestions.

Thanks!