is it possible to select all points in a polygon by the selection of a polygon? Can the summary widget then count the selected points in operations dashboard? It should work like the function Aggregate Points in AGOL Analysis without creating a new layer.
Thanks for your help,
FYI, the new web browser-based Operations Dashboard for ArcGIS can do this. You can enable interactivity in the map element, where an end user could select a polygon in an operational layer and it could select features in another layer. This could also filters in other elements like the serial chart.
Hope this helps,