@TJonesAOC You can not. A pivot table is "re-calculated" in place as soon as you apply a filter or collapse/expand a group. Rows are not synchronised with data entered outside the pivot table. You would have to put the Agency at the top of the Row area and work your way down without filtering/collapsing.
Or choose a totally different approach using a structured table and apply a filter on the Agency column. How exactly depends on the underlying data.