ASP.NET MVC：处理多个布局

I have diffrent group and I need to show the related page for each group. so when a user open the app, I need to first check the user's groupID, if it's 0 pop up a window and ask the group and save it, if it has groupID load the related page. I don't have one layout as a start page and it depends on the user's groupID which page should load up. I have diffrent group and I need to show the re