In the eight week of Fortnite Season 5 you’ll have to find a treasure in “Fortnite Battle Royale” again (Search between 3 oversized seats).
As with other weekly treasure challenges of this kind, you can go straight to the treasure, the exact location you see in the video below.
At the point in the video you can find the golden star symbol. Then finish the game or get killed to properly save the challenge. If you just leave the game without dying, it may not refresh the challenge. You can see everything under the Battle Pass challenges in the lobby. You need a Battle Pass for 1000 V-Bucks to unlock weekly challenges!
An overview of all challenges of the 8th week of Season 5 can be found here.
Search between 3 oversized seats - Week 8
The 3 oversized seats can be found near Flush Factory. The toilet is directly in place, the other two seats can be found on Flush Factory. Right in the middle is a hill on which the star is hidden.