Is there a function to "hide" an attributed based on another Attribute

I see somebody asked this back in 2012 an anywhere from that point forward but I don't see anything in the process template that would suggest it was actually implemented.
I need to be able to hide in the presentation field Z when field Y is set to a specific value
e.g. Y - Internal or External
Z = Documents required Y or N
If Y = External then Z should not be available for population
If Y = Internal then Z should be available for populate
Is that doable ? if not directly, is it doable in a javascript ?