https://www.gamespot.com/articles/fortnite-follow-the-treasure-map-in-dusty-divot-we/1100-6461383/

It took a little longer than usual, but a new set of weekly challenges is now available in Fortnite, whether you're playing on PS4, Xbox One, PC, Nintendo Switch, or mobile. As has been the case this entire season, Week 7's challenges are divided up into two categories--those available to all players and those exclusive to Battle Pass owners--and they run the gamut from straightforward tasks to some that require a bit more legwork.

The trickiest of the bunch this week is to follow the treasure map found in Dusty Divot. The map in question is located in one of the buildings on the western side of the area, but you don't need to actually find it in-game in order to complete the challenge; if you already know where it leads to, you can simply head to that location and claim the Battle Star. In this case, the map points you to a trio of trees just past the large stone head located northwest of Dusty Divot's warehouse.