Lets say I have 4 terminals opened. If I click the terminal launcher icon it maximizes all terminal windows. If I click again it shows all of them in a windows lists fashion so I can click a specific window from the list to go to it. But how can I click again to minimize/hide them all.
Essentially you can't. There is (was) an open bug about this, but the Unity developers/designers marked it as won't fix, despite over 100 people marking it as "affects me". So essentially... no.