Harsha,
Yes, it allows filtering and is, overall, quite simple to use. When I took the test last April I used the ability to mark a few questions that I wanted to go back and review if I had time and I used the filtering functionality to get back to those marked questions. It's really quite easy/obvious how it works once you get into it. Of the many things that we all worry about when anticipating taking the exam, this needn't be one of them!
Best of luck!
Tracy