Filtering by group in pivot table
 

I'm using a pivot table in Excel 2010. In my value field I want to filter out any values below a certain number (it's summing based on multiple values for a single organization). I've done this by creating a group with all of my organizations with the lower values. It works well, but when I try to use other filters through the regular filter or a slicer some (but not all) of the organizations with lower values start showing up again. Any idea as to why this would happen?