IQuery query = session.CreateQuery("from OfflineShipmentLineItem as line join fetch line.Shipment as shipment join fetch line.Extension where shipment.ShipmentDate = :date");
query.SetParameter("date", date);

return query.List<OfflineShipmentLineItem>();

ICriteria criteria = session.CreateCriteria(typeof(OfflineShipmentLineItem));

criteria.SetFetchMode("Shipment", FetchMode.Eager);
criteria.SetFetchMode("Extension", FetchMode.Eager);

criteria.CreateAlias("Shipment", "shipment");

criteria.Add(Expression.Eq("shipment.ShipmentDate", date));

return criteria.List<OfflineShipmentLineItem>();