This question already has an answer here:
I am trying to find a way to su to a user and run a graphical applications (My goal is to run another instance of google drive but for now - just running any application would be fine). I am basically looking for an equivalent of xhost + from Linux.
Currently when I try running iTerm for example as a different user I get:
FAILED TO establish the default connection to the WindowServer
So how can I accomplish this?