Is it possible to expand the domain values ​​in a smart form based on a chosen field?

[HansvanBuggenum]

Hi,

Is it possible to expand the domain values ​​in a smart form based on a chosen field?
Suppose we have a field with 3 options. A, B and C. A field with the options 1,2,3,4. 
If A is selected in the first field, the second field must only show options 1 and 2, if B is selected, 1 and 3 must be shown in the second field, etc.
Can this be set in a smart form? (ArcGis Portal 11.1)

[EmilyGeo]

Hi @HansvanBuggenum, 

You can do this by setting up subtypes in ArcGIS Pro. You can designate a subtype field that will categorize features into different subtypes. Then you can customize domains as well as default values for each subtype. Those will be honored in the smart form.

[HansvanBuggenum]

Hi,

That doesn't seem like an option. It looks like I have to create a new field first and then I can create a subtype for that filed. I can not create a subtype on existing fields. It concerns an existing feature class with a lot of data.