https://www.gamespot.com/articles/fortnite-location-of-greasy-grove-treasure-map-dis/1100-6459319/

Fortnite: Battle Royale challenges for Week 5 of Season 4 are live. Anyone who owns the Battle Pass on PS4, Xbox One, PC, or mobile can now take on another set of seven objectives. There are the usual, more routine ones to do, but there are others--such as the Greasy Grove treasure map--that points to a location you may need some help finding. You'll also need the cooperation of other players to do some dancing. Here's where to find all of the Week 5 challenges and how to compete them.