To get to this page go to my tasks then view task on the task that needs work amending. 

To facilitate tasks that involve one or multiple review stages, you can utilize the 'Revision to be made by' and 'Revision to be checked by' fields to tailor the sequence of individuals who will approve the requested changes before presenting them to you for final approval. Once the 'Main Ask' and its review are finalized, the task will be marked as delivered. At this stage, the task owner can request revisions from both the reviewer and the assignee who completed the 'Main Ask.' Users can select the assignee responsible for the revisions and initiate the request by specifying the required revisions and forwarding the task. It's that simple!

When the 'Main ask' is completed and the review is completed the task will be in a delivered state. When a task is in this state the task owner can request amends from both the reviewer and the assignee that completed the 'Main Ask'.   

Users can then select an assignee that needs to amend their work and send the task back to them.  All they need to do is select the assignee , type the required revisions and then send the request.