It's a field skill, you clicked on a rock/boulder and you had ninja in your team who had skill ''rubble'' that can remove them to make shorcuts. There is also rock climbing that, that allows you to jump, seal that lets you open seals lol and ''dojutsu'' which is some eye skill, lets you see hidden stuff. Rock climbing is found on your main, so everyone always has it, the other 3 are found on other ninjas and they have to be in your current 7 ninja team for them to work.