In the case I faced, the person also had good non-anonymous performance feedback from colleagues, but in 1-1s their collegues shared they were afraid to contradict them because of their aggressive demeanor and how convinced they were they were always right.
But let's assume this is not the case and the director is really mobbing them. In that case, I'd first go directly to them and ask them plainly what they are saying about my performance and why? You might be surprised at the results (and also point both sides at Radical Candor).
But if that does not work, and you've tried going to HR, their superior and their peers, and none of it helped, the only obvious choice is to leave (why stay at an org like that?) if you can afford it (at one of my previous jobs, I confronted the director myself, who ended up agreeing with me but still promoted another person over me for very dubious reasons — when I felt I was being devalued, I've moved my value elsewhere).
Basically, if it is a situation where one is not being recognized and there is no obvious way to fix that (talking to them directly, their superior, HR, their peers), the most reasonable thing is to leave