Restricting Employee Access to Confirmed Time Entries

The client has the following time reporting setup:

1. Employee: Reports and confirms time.
2. Line Manager: Authorizes time.
3. Project Manager: Approves time.

In cases where a correction is required for project transactions, the current process involves the following steps:

1. The Project Manager rejects the time entry.
2. The Line Manager unauthorizes the time.
3. The Employee unconfirms the time entry and makes the necessary corrections.

Currently, employees are able to edit their time reporting without the time being unauthorized. The client is seeking to restrict this functionality so that employees cannot make edits to confirmed time unless the time has first been unauthorized by the Line Manager.

Is there a way to restrict this functionality?

Any suggestions or advice would be greatly appreciated.

Thank you!

Timasha Fernando