You can configure child products to hide under their parent products unless expanded.

Default behavior

When product actions are set with a defined parent/child relationship, by default, child products are indented as in the following:

Collapsible behavior

This behavior can be overridden by adding {“hierarchyColumn”: “<productListColumnVariableName>”} to the value column of the productList element in the layout editor or in the layout CSV file.

Result

Admins can change where the collapse arrow appears by defining a different product list column as the hierarchy column (“hierarchyColumn”). For example, using quantity in the CSV snippet above results in the following: