In Field Maps, you can have an Arcade expression to automatically populate a value based on some other layer, but how are you identifying the "correct" feature from layer 1 to bring into layer 2? Should it just grab attributes from the first feature it happens to intersect with? Or are there other shared attributes involved?
I'm afraid this sort of thing wouldn't work in the Map Viewer, but could work in a field calculation done outside of a map, just not at the same time as the feature being created.
- Josh Carlson
Kendall County GIS