@Jud_Johnson no need telling me it doens’t exist yet 
Point is that most of us don’t have Lightroom, and as many of us don’t even use Windows, we can’t just install it to check, so if you ask for help regarding some Lightroom effect, be sure to supply before|after pictures which show what that effect does, or a link to documentation which demonstrates that clearly.
Thanks @martin_malepo, that demonstrates it well. Lightroom’s shadows/highlights sliders do some smart things under the hood, and I know of no libre photo program which has equivalents.
(clarification: I’m not saying that libre programs can’t recover shadows and highlights, but that the ones I know don’t have tools which work in a comparable way)
The way things go, usually one starts with a research paper, then someone implements the idea, and someone else helps with the UI. If you find a paper which explains how LR’s shadows/highlights tools work under the bonnet, then perhaps someone can try implementing them.