You can use the airside connection between terminal 2 and terminal 3 IF, and I repeat IF, you already have your boarding pass for the international flight. Right as you enter the airside connection in the domestic part of Terminal 2. the boarding pass has to be read and then you go thru security.

This video may be helpful: https://yhoo.it/2Lj16aM

They did not film in the security area or Passport control. Ignore after the 4:35 mark as when you turn the corner into Terminal 3 that is where the aforementioned escalator now takes you up. You eventually come out post passport control in terminal 3.

What I also found, is that while the domestic airline provided a boarding pass for the international flight, allowing me to do the above, the international airline preferred their own boarding pass, and you can change that by going to the departure gate, if you need to do so.