Simple list within another list?

Good! I'm doing an exercise where I have a simple list of objects and I want to add another list to each object in that list, either single or double?

for example:

  public class Lista_Simple {

  Nodo Primero;
  int Longitud;
  frmEstudiante es = new frmEstudiante();

  public Lista_Simple() {
    Primero = null;
  }

  public boolean isVacio() {
    return Primero == null;
  }

  public void Ingresar(Miembro_Universidad dato) {
    Nodo nuevo = new Nodo(dato);
    if (isVacio()) {
      setPrimero(nuevo);
    } else {
      Nodo puntero = Primero;
      while (puntero.Siguiente != null) {
        puntero = puntero.getSiguiente();
      }
      puntero.setSiguiente(nuevo);
    }
    Longitud++;
  }
}

That is my list of students, so I want to add to each student another list of course examples.

How could I?