Expression to change symbology of one layer based on data from another

[janderson_ksninc]

I'm working on a web map for the civil engineering firm that I work for to be used in the field where one layer is symbolized from values in another layer. I read a post/lesson called, "Access attributes from another layer with ArcGIS Arcade" and tried to modify and use that lesson for my use case but have not had any luck so far. 

I have a couple questions that hopefully someone can answer:

1. Is it possible to have one layer's symbology driven by values in another layer?

2. If so, can you please point me in the right direction?

Any help anyone could provide would be a huge help as this is one of the last things I need to do before going into the field this week.

[jcarlson]

Arcade has a number of different profiles, each with differing scopes and capabilities. Symbology is one of the most constrained, only able to access other attributes of a single feature, not even other features in the same layer, and certainly not features in another layer entirely.

A possible workaround is to join the layers together, but this will only work if the layers share an attribute. It also does not translate over to a web map unless you created a hosted feature layer view, which comes with its own requirements, first and foremost that both layers being joined must be hosted layers owned by the same user.