public class X
{
    private String foo;
}

@Inheritance(strategy=InheritanceType.JOINED)
public class A
{
    private X myX;
}

public class B
extends A
{
    
}

public class C
extends A
{
    private B myB;
}

Criteria crit = session.createCriteria(C.class);
// what alias do I need to create here?
crit.addOrder(Order.asc("myB.myX.foo"))