Minecraft 3x3 Piston goal?

I'm currently building on a Creativserver with my friends. I'm building a bunker and try to build a 3x3 gate… That worked too… But I did not quite reach it… Hemand knows a turtorial in which a 3x3 goal is built which pushes the blocks but one more block forward and one can open from inside and outside?

The "which pushes the gate blocks but still 1 block forward" is called "Flush", if I understand you correctly.

How about this? :

Opening from inside and outside is no problem - Just a button on both sides.