Hi Ralf
Unfortunately, the slider approximation is the Selective Tonality sliders but they introduce all sorts of problems.
Instead of producing nice smooth gradations, they contribute to “stairstep” or “sawtooth” changes. See my post here…
… and here…
In fact that whole thread and others it links to should explain more why I prefer to use the Tone Curve over the Selective Tonality sliders.
Essentially, the Tone Curve allows you to increase contrast by making the curve steeper and decrease contrast by making the curve shallower.
Could you share an example image that we can compare and I can show you how to construct a suitable Tone Curve?