CPS doesn’t reveal where they get their content, but you can search up sample questions from OLSAT, CogAT or NNAT as a place to start.

Two entities better equipped to answer this are http://www.testprepchicago.com and https://www.thecriticalthinkingchild.com/.

Selective Prep provides academic center test prep courses.  https://selectiveprep.com/

I think SP has done the academic center courses for years, Test Prep Chicago is a newer provider.