Hi,

You can filter the products by using the field product_type. If you need to show only the products having consumable and service products in the sale order lines. You can override the product_id field and you can add the domain:

domain ="[('product_type', 'in' ,['consu','service'])]"

or if you need only any single product type you can use "=" operation

domain ="[('product_type', '=' ,'consu')]"

Hope it helps