To unlock this achievement you have to go to Level select. Choose the level you wanna to do this on & when u select the level a drop down will pop down and show u your best round on that hole along with the green circles with images on them. Use your left joystick to move to Stroke Attack - the middle one with the 2 golf sticks and ball in the middle
I did it on level 7 which is a automatic hole in 1. The best shot on level is 1 stroke & i got a hole in 1 & the achievement popped after finishing the level.