Generally, you have to ask doctors already in the know. You find the top academic medical center in your area, and you ask the relevant specialist there who the absolute top person in their field is for a second opinion.
It's not always a guaranteed correct answer - I know for a fact of some people at absolutely top ranked institutions, with top pedigrees, who clearly got there by academic skills and are absolute shit as clinicians - but for the most part, it'll get you where you need to go. Generally the only way you'll end up with one of those shiny pieces of shit is if referred to them strictly by reputation; no one that's worked with them would make that referral.
It's also an answer likely to overlook excellent clinicians - many (many!, maybe most) very good clinicians aren't academics, and this won't route you to them. But you're okay with overlooking excellent docs, as long as you end up at a top doc.
Finding excellent doctors without shiny pedigrees is not something a layman can do. It's just something that local docs eventually come to know about other docs in their social-professional network, and by no means is it an unbiased assessment.
If all you have available is people's online CVs, look strongly at people with mediocre or shitty medical schools and highly prestigious residencies and fellowships. Those are people who had networking and social signaling working actively against them, and managed to positively impress everyone they worked with. E.g., a buddy of mine got into a shit medical school, and got one of the country's most prestigious subspecialties in a prestigious institution. He had to impress every single person he worked with, had to do surpass everyone on his standardized exams, and otherwise be top-of-the-top in every way. He's a ridiculously top-notch doc.