Hi there,
I have attached a patch which adds a new capability to the 
‘ns-hide-emacs’ function in the NS port.  Specifically, it causes 
the ‘ns-hide-emacs’ function to respond to being called with the 
argument 'activate-front in a similar way to how it responds when 
called with 'activate.  The difference is, instead of layering 
every Emacs frame in front of every other application’s windows, 
it only brings the selected frame forward.  I have uploaded a 
small video of the new functionality in action here: 
https://mfa.pw/activate-front.mp4

Please let me know if any modifications would need to be made to
this patch before it could be accepted.

Thanks for your time,
Matt