Where do you find crustle in poke park 2 wonders beyond?

Do you mean Crustle in the CRAG AREA? Go to ROCKRIDGE FORT where you met TEPIG. There are some tall platforms you have to go to. One of them has a small treasure box that SPINS SLOWLY. If you see this, do you notice the STRANGE ROCK near you? That's a DWEBBLE in the dirt. All you need to do is splash it with Water Gun, Oshawott! Lol! Lol! Lol! Lol!

It worked for me. Dwebble came out and friends you. Now, you go up the SPIRAL BRIDGE and once you are at the top, GO STRAIGHT but NOT the one on your right. If you have not yet, BREAK ALL the LARGE ROCKS in ALL the AREAS! Then talk to Crustle and he said thank you for breaking rocks be my friend.