Group parts and single parts LIST : incorrect parts quantity

Hi,

I am trying to create a report showing the assembly member/number with the respective parts/fittings. When I select a construction group list, run the report, the assembly shows the quantity correct but the parts listed only lists for only one assembly/group. Please refer to the screenshot below, GR17, we have 2 of this, but the fittings/parts listed is only for one assembly/group. How do we make those parts'quantity be listed as a total for the total number of assembly/groups.