Way to reference the built-in "Function" door parameter in other formulas

[AlexLibengood]

Revit's door families have a built-in parameter named "Function" with a drop -down that allows you to set whether the door is an "Interior" or "Exterior" door.

Is it possible to reference this parameter in other parameter formulas?  For example, if the door function is set to "Exterior", I want the door threshold visibility to be turned on, but if it is set to "Interior", then the threshold visibility should be set to off.

As seen above, just trying to reference the parameter by it's name doesn't work.

I could just have the user control the threshold visibility with another yes/no parameter, but it would be a lot simpler for them to just rely on the built-in Function parameter since we're already using that in our schedules and not have to worry about the threshold visibility in addition to that.  So if someone knows how to reference that built-in parameter, I would be grateful to know how!

Thanks!

[ToanDN · Accepted solution]

Function is a Type parameter so I would create different types for Interior and Exterior then set the threshold visibility per type.  It is a one time setting for each type so it is not that bad.