Can requester, recipient and approver change input parameters once the request is raised?

You can easily allow approvers to change the parameters if you select the checkbox Editable for approver on your request properties.

By default, the requester and the recipient cannot change the parameters. What would you do if you have a 2 step approval workflow and the recipient decides after the 1 approver level as decided that he changes an important parameter the approver has based his decision on?

You can easily allow approvers to change the parameters if you select the checkbox Editable for approver on your request properties.

By default, the requester and the recipient cannot change the parameters. What would you do if you have a 2 step approval workflow and the recipient decides after the 1 approver level as decided that he changes an important parameter the approver has based his decision on?

Hi Markus, 

Requester should be only allowed to edit details before any approval. in case of 2 step approval if request is approved at level 1 then only 2nd approver  should be able to edit it, not the requester or 1st level approver.

In this case, shall we able to achieve via configuration changes.     As per your update it will be editable only to current approver in request.

It works as described ootb. If you need a different behavior you have to follow the post from Geraldine Hopf.