https://www.gamespot.com/articles/fortnite-week-5-challenges-greasy-grove-treasure-m/1100-6459319/

Week 5 challenges in Fortnite: Battle Royale are live, presenting Season 4 Battle Pass owners with another set of seven objectives to complete. These include some fairly routine objectives--one of which is bugged as of this writing--while a trickier one involves tracking down a Greasy Grove treasure map. More importantly, you'll need the cooperation of other players to do some dancing.