Blurring different levels

Hello, I’m building an AS2.0 website and was planning on having all external files that get loaded into one main file. I would tell what level for each external piece to be at. I’m just wondering if I can blur different levels.

I’ve seen some sites that when you click a button the are viewing the top most layer everything underneath it is blurred. Can you target individual levels to be blurred?

Thanks for any help!