You can save a session variable with the user access level from the login page... By default it will use the same name as the column in the database, so let's assume it is "UserAccess" although you can set it to whatever you want.
Then you can create rules for each access level. One rule might be:
"Admin" and it might be set to "Allow If Session variable "UserAccess" equal to 4
You can then use that rule to restrict access to admin users only, Hopefully that helps.