The scope of the savepoint is a transaction in which it is defined. The Savepoints defined in the major transaction are not related to the savepoints defined in its autonomous transactions. However, the major transaction and an autonomous transaction can use similar savepoint names.
You can roll back only to savepoints marked in the present transaction. Therefore, when in an autonomous transaction, you cannot roll back to the savepoint marked in the major transaction. To do so, you should resume the major transaction by exiting the autonomous routine.
If in the main transaction, the rolling back to a savepoint marked before you started an autonomous transaction does not roll back the autonomous transaction. Keep in mind, that the autonomous transactions are fully independent of the major transaction.