The 2nd Grouping (and 1st Grouping) options are available on two reports:
Inventory Sales Analysis Report and Inventory Purchase Analysis Report:
None - Do not group items. Items are not sub-totaled by group.
Department - Group by Department, sub-total by Department.
Category - Group by Category, sub-total by Category.
Location - Group by Location, sub-total by Location.
See:
Report Manager - Group By Screen
Report Manager Contents