I attached an image of what my Plug-Ins
folder looks like. Note the items in the Components
folder - I believe these are the ones that will be used instead of the VST ones, and are recommended since you're on a Mac. (I'm running OS X 10.11.3.)
From Kontakt 5 Player Getting Started English
"Depending on your operating system and choices upon installation, KONTAKT provides VST, Audio Units, and RTAS plug-in formats. Refer to the documentation of your sequencer to find out which of these formats is the right one in your case; if you have enabled the appropriate format at installation time, KONTAKT 5 should appear in the plug-in selection list inside your sequencer. If it is not the case, re-run the installer and make sure the appropriate plug-in is marked for installation."
If I'm reading that right, rerunning the KP5 installer and checking the AU plugin box should place it where it needs to go.