Multiple ASP.NET Membership roles in the same Website

In my MVC3 application I have ASP.NET Membership roles like - Manager, System Admin and EditorI am using Windows Authentication for the website and I am adding the users in the Network to the Membership just like in the following example -
http://weblogs.asp.net/scottgu/pages/Recipe_3A00_-Implementing-Role_2D00_Based-Security-with-ASP.NET-2.0-using-Windows-Authentication-and-SQL-Server.aspx
But, my problem is there are people who require multiple permissions. For example
User-John is the Manager of Department-ABC and he can see all the Actions in Department-ABC.User-John is also Editor in Department-XYZ and he should be able ...