Is there an equivalent of Bayesian optimization that works only with comparative results?

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Hello everyone, I'm working on a problem where I need to find the best set of parameters (10 of them) that optimises a very costly objective function. Normally, I would use a Bayesian optimisation, but in this specific case, I don't have access to the actual objective function, the only thing that I can calculate is weather the function is higher with a certain set of parameters A or B. I don't know how the actual values of the function, nor its derivatives. All I can do is to compare the two set of parameters and tell which one produces a lower value of the function.