- I have a polygon regions layer.
- I have a number of other layers that have already been pre-clipped to these regions
- The region ID is included for every feature
Bit like this, the boxes are the regions:

End goal:
As a user, I want to choose a region from a dropdown, and then this opens a web map/web app with only the relevant features being shown and centered into the relevant bounding box for that region.
The bit I am struggling to work out, is a good approach to do the bit in red above. Everything else is ok.
Some ideas:
- I could automate creating a series of web maps with relevant filters applied to each of the layers, and then I could use the relevant Web Map ID in a URL parameters.
- I don't like this, as will end up with lots of web maps and will be tricker if I need to update a popup/style for all of them.
- I was hoping that I could apply a filter to all of the layers in my web map purely through using a URL parameter. I do not think this is possible?
- AppBuilder might be a bit of a heavy app for this, but even with a hidden filter widget, I do not think I can use a URL parameter to call an app to filter all layers with a def query.
- If I was to go down the JS API route, it looks like I could possibly achieve what I want with featureLayer.setDefinitionExpression="regionID"
Just looking to brainstorm any ideas or send me some relevant links so I can do some homework before going down the wrong path. Thanks!