How to use Debugfloat3Values?

I am playing around in material editors.

I hooked up Object Position in my material to change base color
and apply it on one of my mesh.
I can see my mesh color changes as I move my mesh around.

But I wanted to check the Object Position value when I move my mesh around.
I hooked up to DebugFloat3Values node but nothing happen.

any ideas?

I would also like to know how to use this material expression. It is not covered in the documentation at all.