I don't know really it is possible or not in analog domain but I am bit confident about this in digital domain.
I am facing this problem in my current work. Why not, we implement this as mentioned in the below picture in labview. If I am wrong with anything, please let me know.
I am just using labview from 2 months and I am not sure this is possible or not. I guess I can not use any filter here for separating exactly those peaks. May be in some systems, peaks shouldn't place always at the same frequency.
I hope you will understand after a look at picture. I just have taken that picture from my notebook. If it is not clear, I will try to give much clear picture.