Hi Joe .... base of my suggestion is the knowledge of luminosity masks and their use in combo with adjustment layers and / or channel blending with blend modes .
In practical .... one has to select the tonal range you want to edit ( i.e. 3/4 tones) via the one of the RGB channels . The easiest way to do that is a panel for photoshop that is numerously floating around the web , get it install it .... and you can start with tonal selections of your choice !!!
Once you have your selection done via that panel , add it as a layer mask to a pixel or adjustment layer to restrict your edit to the selected tonal range . You can darken , lighten , add more tone , color or contrast . And you can even select the intensity via opacity of that layer . Does sound complicated but it is not !!!
Hope this helps
Cheers Andreas
https://www.google.com/url?sa=t&rct=...WvW4l_UIV_AA4V
Have a look at his website , Panel is free via Adobe Exchange .... but you could support him with some cookies of your choice .