On my machine, the watch window was docket at the bottom of the screen.
I clicked on the word "Watches" at the top of the watch window. The bar across the top of the window went blue. Then I was able to drag it out and drop it in the middle of my screen.
Next I drag the same "Watches" top bar to the top of my editor window, i.e. to the top of the code. The top of the editor window gets shaded blue. Then I can drop it there and it is over the code.
That's "over" in the sense of "above it on the screen". I didn't find a way to make it cover all the source code. But I would think you need to be able to see the source code to know where you are debugging.
