I know it's possible to create an expression within pop-ups that relates the feature with features in another layer, but I'm trying to extend this capability to symbology. I have an expression that works in pop-ups to count the number of features of another layer that fall within a specific buffer of the current feature. I want to be able to symbolize based on that count, but the same expression does not work within symbology. I know I could calculate this in the data layer with adding another field, but I was hoping not to do that and I definitely want the calculation to be dynamic.
My expression that works in the pop-up is essentially what is explained here: https://www.esri.com/arcgis-blog/products/arcgis-online/analytics/use-arcade-geometry-functions/#:~:text=the%20farmer%E2%80%99s%20markets-,.,-How%20to%20display
