Clear Global Caches can be located at Admin Dashboard/Admin Home/Tools section:

#Clear Global Caches.

By pressing on Clear Global Caches, it will execute clearing your Caches files in [yourmoosocial/app/tmp/cache]

After pressing on Clear Global Caches, the message will display tell you all caches had been cleared:

#Message displayed.

This is what happened:

#The caches have been cleared.