Allow filtering of data based on symbology categories configured in the web map
I have a dataset of libraries in AGOL where the symbology of the library features is configured in the web map using an expression (which is a simple calculation based on two attributes in the library dataset).
I want to use this web map in a Dashboard but I want the user to be able to use the Category Selector to filter the map based on the same categories that drive the symbology in the web map. This seems like a relatively simple request (and I'm surprised that nobody else has hit this limitation) but it just doesn't seem to be possible. The Category Selector only works on attributes in the actual hosted feature layer, attribute expressions defined in the web map are not visible in the Dashboard. You can write a data expression in the Dashboard to drive the Category Selector, but this has to return a FeatureSet and it's not then possible to link this back to the features in the web map (to filter the data) because there isn't a matching field in the hosted feature layer to link the two things together.
This idea is to expose attribute expressions that are configured in the web map in Dashboards. Any attribute expressions configured in the web map already appear in the 'Fields' area in Map Viewer so it's feels like it should be relatively straight forward to expose these for use in Dashboards.
Screen grabs of my scenario below that hopefully explain the issue.
My dataset of libraries has two attributes: capacity (integer) and current occupancy (integer). In the web map, I have configured the libraries to be displayed with a colour based on how busy the library currently is (this is calculated by working out the current percentage occupancy ((currentoccupancy/capacity) * 100) and then classifying the value in to 'quiet', 'busy', 'very busy', 'full', and 'no data'):
This information is also displayed in the popup using an Attribute Expression:
What I want in the Dashboard is the ability to configure a Category Selector to allow users to filter the map data to just show those libraries that are currently 'quiet', i.e. something like this:
From what I can tell, there is no way to do this even though using simple attribute expressions to display data in web maps is a really common way of presenting data.
This was originally posted as a question in the ArcGIS Dashboard Questions forum: https://community.esri.com/t5/arcgis-dashboards-questions/category-selector-doesn-t-use-virtual-fiel...