users are able to unapprove journals which are created and approved by his next level

users are able to view the  'Unapprove' button on the journals created by his superior, 'Unapprove buttion ' is enabled once the journal was approved by the manager

Example:

User1 in level1 and his supervisor was user2 who is in level2.

The hierechary here was:

Journals created by User1 should be approved User2

Journals created by User 2 should be approved by User3.

The question here is

User2 has created a journal and it was approved successfully by user3.

Now User 1 and aswell User2 were able to 'Unapprove' the journal.

Questions:

1) Is this the intended functionality provided by Oracle?

2)Is there any way to restrict the 'Unapprove' to level 1 and Levl2  and only the approver (user3) should be able to unapprov.