For instance, if you see that applicants that are otherwise equally qualified are getting rejected on recruiter screen disproportionally by race, you may have an issue with how your screening is done. And yes, this happens: https://eml.berkeley.edu//~crwalters/papers/randres.pdf
A reasonable goal is that race, gender, and sexual orientation should have no bearing at all on how likely it is that you get hired, promoted, or fired. So these inputs are typically blinded to hiring managers but available to HR in aggregate to let them perform these kinds of analyses.
I'll acknowledge this approach leads to some very odd interactions, like my school district asking what the sexual orientation of my five year old is. But it's not clear how else one can build a credible gauge for measuring and eliminating *isms from a system. (Open to hearing ideas!)