If I understand this correctly, I think the easiest thing to do would be to create called "Avg. Hours per Week" and type in "34.16".
Use this field to create your planned hours (Total Employees*Avg. Hours per Week). In the attached workbook, it seems to be filtering appropriately with your 2,3, and 4 week filters.
Hope this helps!
planning hours.twbx 1.6 MB