app/pb_kits/playbook/pb_table/docs/_table_with_collapsible_rails

The collapsible prop can be used on any Table Row to add a collapsible area. Use the additional collapsible_content prop to add any content to the collapsible Row.
Please be aware that you will need to pass in an id to any table rows you want to be collapsible. Make sure every id is unique if you are using multipe collapsibles.