Hello @GBacon,
My recommendation is to apply the filter at the layer level before creating the custom data. You can do the following inside the BA web app:
1. Expand the layer and click Filter by attribute option
2. Apply your filter and click Save as a new layer at the bottom
3. Use the new filtered layer for custom data
I see that you are using point feature layer for your custom data input. Please note that the values of all the point features inside your study area will be summarized using this approach.
I am not sure if this works for you but you can also explore using your point feature layer as input to create a nearby table.
The nearby workflow allows you to filter your input layer by attribute:
Then you can summarize the numeric values of all the point features inside your study area in the nearby table as follows:
I hope this helps,
Fasil T.