I’ve created a project where tasks are added as intake forms are submitted. Once the submitter has completed the form, they are added to the task that is created from the form as a “Commenter” only. The task generated from that form then routes through a series of approvals.
I want the users who are assigned to review and approve to still have the ability to ask questions to the user that originally submitted the form, but I don’t want the original submitter to see the subtasks and comments the reviewers are having with each other while they decide if this request should be approved or not.
When someone is added as a collaborator to a task, they can see the full comment thread and subtasks.
So you’d have to carry out this work in two separate tasks, one including the form submitter and one not, and relegate the discussion as appropriate, in order to achieve the two different access rights you need.
Sometimes folks address this by adding the form submitter to a subtask only and that becomes the more public thread, and the parent task and any other subtasks are excluded from the form submitter.