Yes, alters can definitely have alters of their own, but it really isn't any more complicated than any other dissociative split. In a way its just an elaborate system of task delegation. (For example... I [host] can't handle a task and delegates x to do it... but x can't handle all of that alone so delegates part of the task to x1 and x2). Once the orginal ability to delegate tasks (split) is there, dissociating can occur in all manner of directions.