The standard group invoice feature of the NetSuite allows us to Group the invoices from different sales orders.
for that create invoices from different sales order and then in the group invoice page we can mark the invoices from different sales orders and group them into a single group invoice.
this is the group invoice created the invoices are SWCC10583 and SWCC10584
In the invoice SWCC10583
The created from field value is
Sales order SO22587
In the invoice SWCC10584
The created from field value is
the sales order is SO22588
that is 2 different sales orders