think works
Criteria criteria = getSession().createCriteria(clazz);
Criterion rest1= Restrictions.and(Restrictions.eq(A, "X"),
Restrictions.in("B", Arrays.asList("X",Y)));
Criterion rest2= Restrictions.and(Restrictions.eq(A, "Y"),
Restrictions.eq(B, "Z"));
criteria.add(Restrictions.or(rest1, rest2));