It has to be on the chunk grid system, which when you do f3 you can see it on your values there at what part of the chunk you're in.
See the "(2)" and the "(4)" for the x and z at the end there? That's the position in the chunk you're in. It goes from 0 to 15. A chunk is the same thing as a plot, so they can only be on the grid systems like this.