Story Related and can't be missed. You will earn this achievement upon completing the third world in this game. When I was going through this game I used the guide below but if you'd rather tackle this alone: you should already know the game mechanics and requirements to complete levels by this point and this mission is no different: find the obs, build new platforms and get more orbs until you're done. Don't forget that you can use LB to get a little more hop in your jump!
CIVITAS starts at 37:55