Since you’ve significant experience as an HR candidate, the interviewers might ask this question to check your decision-making abilities. The best answer you could give in this situation is something like this, “There’s no doubt that at times as an HR, I might have to face such situations where two candidates have equivalent qualifications. In that case, I would try to hire both of them if there's a requirement for two candidates, and if not, then I would choose one among them depending upon their zeal for work, problem-solving abilities, and knowledge about the post they’ve applied for. If possible and needed, I would take an aptitude test and choose the one who has managed to score better. After all, as an HR, it’s my responsibility to choose the best candidate for my organization.”