Purchase Orders Saved Search Vendor Filter

We have a saved search which lists all purchase orders. In the results section, we are using Name field to list the vendors (Preferred Vendor field is coming up blank). We are also using the Name field as a filter. But it lists vendors and customers in the multi-select. This makes it very difficult to select vendors only.

So our need is to simply list all Purchase Orders and be able to filter the list by the vendor (among other things). See below screenshots.

The results screen shows both vendors (green arrow) and customers (red arrow).

We do not want the customers in the filter multi-select. My gut says that on both the Results tab and Available Filters tab we need to use another field other than Name or Preferred Vendor (as stated, Preferred Vendor show no data in the saved search output)