The ten areas of the CISSP Common Body of Knowledge

The parent organization for the CISSP, the ISC-squared, is pretty quiet on the subject of how job duties and responsibilies map to each of the 10 areas in the CBK. Since you already have a CISSP, forgive me for observing that point should be nearly moot, except obviously that you're trying to figure out how to put your knowledge to work in the workplace. But having obtained the CISSP, you have been able to convince them that you had at least three years of relevant work experience, as well as passing the test. I might therefore ask you to revisit your application and see how you made the case to qualify to meet the on-the-job experience requirement.

That said, it's probably best to let your technical interests guide further work and training. If IDS are what excite you, you are correct in observing that SANS offers training and certification on that subject (as do numerous vendors, including ISS, Computer Associates, Network Associates and many others).

I'm sorry I can't point you to specific lists of job duties or aptitude tests or self-assessments to help you figure where to specialize. My advice is to continue to read widely in the field, and to concentrate in those areas where your interest and enthusiasm are highest. With a 13-to-1 ratio of jobs to qualified candidates, the security field is one where you can try out various roles before settling into the one you like best.