Trending @Accenture; Proficiency test

Hi grapeviners, my Primary skill is Agile testing and I need to attempt the proficiency exam for it for performance evaluation for mid year cycle. How do I prepare for it? ps: for my other skill which is “functional test planning “ I had prepared from previous years istqb questions but only 1% of those questions were asked in the proficiency test. Please suggest any other better source?