There are probably a few ways you can get this done but one of the easiest may be to have different menus that you conditionally use depending on the user level.
You could implement something like this by first creating the menus in Menu Writer. You would craft each unique menu here.
Then on your template page where you would have a reference to the menu file you can add in references to the other menus. When they are all on the page you can add in some if statements or a switch statement so that only one of them is used.
Every time you create another menu in the site there will be a new menu in the menu writer folder. They will be prefixed with 0, then 1 and so on. If you craft this correctly you could just use a single reference for the menu file and concatenate the user group session variable that holds one of the corresponding values for the menu you would like to display. This part is a little advanced but would give you the same result.
If you have any problems with any part of this let me know and I can give you some pointers.
