Hi,

Suppose if you want to sell a group of a product like a Kit to the customer,  you can use the option kit in the BOM.

Let you have product A, B, and C, you want to sell it as Kit, named Combo ABC, you can set the bill of material for the Product Combo ABC and add the components as Product A, B, and C.

So when you select the Product Combo ABC in sale order, then its delivery order the product Combo ABC will get replaced by its components in Bill of material.

Refer this Doc too: https://www.odoo.com/documentation/user/10.0/manufacturing/overview/bill_of_materials/kit_shipping.html

Thanks