AutoInvoice Grouping Rules
Grouping rules specify attributes that must be identical for lines to be created as one transaction. Grouping rules always include the mandatory attributes, and to this is added optional attributes that you define in the grouping rule.
Grouping rules tell AutoInvoice how you want to group records in the interface tables into invoices, debit memos, and credit memos. Grouping rules specify which attributes must be identical for lines to appear on the same transaction.
All grouping rules you define implicitly include mandatory attributes plus the optional attributes you define. So if you want to refine the grouping of transaction records, you can use the Optional Grouping Attributes to do so.
All transaction records having the same Grouping Attributes (Mandatory and Optional) are grouped into the same transaction.
Responsibility: Receivables Manager
Navigation: Setup > Transactions > AutoInvoice > Grouping Rules
As per the grouping rules the grouping happens based upon Interface Line Attribute1 for invoice class.