"Fortunately, I have never had to resolved cash flow issues. I believe my high degree of meticulousness ensured such situation would rarely occur as I always review my work numerous times before submission to ensure the information is accurate."
Tell the interviewer about the biggest cash flow issue you have resolved in your career, in any position (i.e., it does not have to be in a formal capacity of Treasury Assistant but can be in a position wherein you had treasury duties).
Should you not have experienced such issues, tell the interviewer why that is the case.
"I would rate myself 9/10 with respect to cash flow, and 6/10 with respect to general analysis. My last roles entailed mostly cash flow related duties, and little general analysis. I am however familiar with general analysis and am more than willing to undertake required training in that area if necessary in order to reach expert level."
You may answer this question by rating yourself on a scale of 1 to 10, and why.
Should you lack skills in certain areas, ensure to mention you are more than willing to undertake training. This will show the interviewer you are committed and are serious about working for this employer.