1. Reviewer 1 will enter the comment
2. Reviewer 2 should able to see the comment entered by Reviewer 1 and enter his own comment in new comment field
3. Reviewer 3 should able to see the comment entered by both the reviewers and enter his own comment in new comment field
4. and it by default workflow initiator will able to see the comments entered by all the reviewers.
how to achieve 2nd and 3rd point?