If you have many Bill of Materials, it may be quicker to bulk import them from Excel into Finale.
The functionality can be under Import / Export section >> Import to batch create & update bill of materials
The format of the each row in the Excel file is
Product ID (parent), Item Index, Child Product ID (item product id), Qty, Notes.
The product id, child product id, qty are mandatory fields.
Notes and item index are optional fields.