A product group is a high-level grouping of the products. Product groups enable you to categorize the products which are displayed on the cart page. When you select the group level checkbox, CPQ auto-selects all the products in the group and allows you to select line items and perform actions such as Copy, Remove From Cart, and Mass Update. You must specify the API names in the Config System Properties > Manage > System Properties > GroupBy Fields. For more information, see Configuring Custom Settings. These line item fields can be of the Lookup, Text, and Formula types.

Viewing subtotal at the group by cart level: You can view the subtotals of the cart by a group so that you can make decisions while applying adjustments at the group line item. When you view a cart by the group, you see the relevant subtotals as separate line items. Group by subtotal has similar columns as Cart Line Item display columns.