Cythia - You should be able to accomplish this using User Filters -- simply map the Divisions to your Security Groups. If you go this route, the row filtering will be automatic and the users won't have to touch anything - they'll automatically see all the rows they should based on their Security Group membership - no more parameters!
Hope this helps!
Yes this looks like it will work much better and it is allowing me to use the security groups I had set up. You are a data ROCK STAR!