There are many special achievements in "Call of Duty: Black Ops 6". Search and Destruction is one of them. If you want to do this achievement, you can use a remote-controlled throwing knife at least 50 meters away during the campaign. It is still difficult to kill two people with a flying knife.
How to obtain the Seek and Destroy achievement in Call of Duty 21 Black Ops 6
Seek and destroy
In the campaign, kill 2 people with a remote-controlled throwing knife from at least 50 meters away
I got this during the "Escape from the Darkside" objective in the "Most Wanted" mission. Before you enter the large computer room (if selected, you can sneak through the large windows on either side of the room), head back until you hit the metal shutters and equip your explosive throwing knife. Aim under the doorframe, turning it downwards and then upwards until there are two enemies on the catwalk shooting at you.
Second chance
Near the end of the mission, a second chance appears in the main ballroom. Once you're in the west wing, aim the knife and throw it onto the stage. Aim down at the 4 enemies in the center of the room.