Maybe someone can help me with this one.

I would like to create a pivot table in which i would like to compare spendings against a preseted plan for various categories and the subsegments of each category.

To do this I intended to add a manual field calculation which subtracts the actual spendings against the plan. Now when I inserted the calculation my pivot table reflects all subsegments for each category. Is there a way to avoid this artificial blow up?