Tell the interviewer about your team management experience, should you have any, in a professional, volunteer, or educational capacity (alternatively).
Should you have none, mention that you are more than willing to gain leadership skills and would love to take on a leadership role - and why you are a good leader.
If the interviewer asks such a question, it is likely that the position entails leadership duties - current or future, which will most of the time already be outlined on the job posting. As such, he/she will assume you applied to this role upon having adequately read the job posting, and that you have an interest in team mananegement and/or team management experience.
Try to provide an example related to treasury as much as possible. If you cannot do so, provide any example by telling the interviewer you are positive your skills will easily be transferable.