color correction not understanding old tutorial

I went here to peruse the tutorial:

The writer describes a box which is visible in his screen shots and dragging it around to affect changes. I am totally clueless as to how to find this “box” on my color module.

Can someone offer advice?

Thank you.

Caruso

In my version of Darktable there isnt a box anymore. But you have two dots in the center.
Which have the effect. A white (highlights) and a gray (shadows) one. Just drag them to the color you want.