Adjust arcade expression when running a model in ModelBuilder

[RyanBohan]

I am working on building a model, and the request is to be able to change some of the variables when running the model.  I know this can be done by Creating a Variable --> From Parameter --> Expression; and setting that as a Parameter.

Ideally, I just want the first part of the arcade expression to be visible and adjustable.

Currently it appears I am showing the entire arcade expression, which makes it a little hard for another user to adjust, also I can't prevent the user from changing the model logic in more ways than I wish to expose to the user.

[RyanBohan · Accepted solution]

A coworker pointed me in the right direction for parameters.  Turns out you can use named variables in an arcade expression, by enclosing it within percents,   Ie %variable%.

var Residential = %Residential%
var Public_Facilities = %Public_Facilities%
var Tourism = %Tourism%
var Commercial_Area = %Commercial_Area%
var High_Traffic = %High_Traffic%
var Open_Space = %Open_Space%

Leaving my question up, for anyone else runs into the same issue.