No, my book does not discuss nested transactions. Actually there is no nested transaction in a Hibernate application. Transactions are handled on the service objects which intermediates the business layer and DAOs.
Hibernate does not contains nested transactions explicitly but you can create a global application transaction which you can handle at the service level in which Spring play a role on this.
Also, I think 'savepoints' can achieve that.
Best Regards, Mohamed El-Refaey