There are quite a few tasks in Gray Zone Warfare that require you to search for a body. Since the first set of these tasks did so, it should come as no surprise that Left Behind II and Last Farewell II ask for the same thing.
Left Behind 2 // Last Farewell 2 | Gray Zone Warfare GUIDE | Mission Tutorial
But unlike the first set of both tasks, where you had to pick one to complete, you can complete and turn in both Left Behind II and Last Farewell II while only setting out once. This task is aided by a fairly obvious marker next to the body you’re looking for, but you should still have an idea of where to go after loading up Gray Zone Warfare.
Before departure, collect a tracker via your messaging screen or purchase one from Gunny or Handshake.
The body is located in the golf course section of the Midnight Sapphire hotel area, in the northern portion of the map, at map coordinates (168, 168). The body is in the upper right corner of the map coordinate square.