The current way approvers are given access to view and edit all of the entries in any form they are an approver for is not satisfactory.
First of all, approvers shouldn't automatically get the right to edit all fields of every entry in the form, just because they can approve submissions. This is not needed in most cases and opens up possibilities of accidental, or even deliberate, alteration of the data. Surely, it is possible to allow them to update the approval field only.
(More fine-grained access control over which fields could be edited by users with permission to edit entries, in general, would be welcome. In fact, more fine-grained access control over which fields could be viewed, by users with permission to view entries, in general, would be welcome. So, a general solution that allowed any full Machform administrator to set access to all fields in an entry to be viewed and/or edited by any user with access to view and/or edit entries in any form, on a user-by-user and form-by-form basis, would be a good thing, in my opinion!)
But, leaving all that wishful thinking aside, the improvement to Machform I am actually asking for in this request is an option to limit the entries that can be viewed by an "approver" to only the entries they have the ability to approve and those they have already approved. An approver only needs to see entries that they can approve. They should not be able to see other entries. (If they do, then a full Machform administrator can give them access to edit entries in general, which would be a separate setting in this scenario.) For example, if there is a single form that allows users to request time off, which is sent to the head of the appropriate department based on a choice from a drop-down "department" menu made by the person filling out the form, there is no reason that the head of each department should be able to see the requests and approvals made in all the other departments. A similar request was made earlier, but it shouldn't be necessary to set up specific logic rules to prevent the head of department A from seeing requests made in department B; it should just happen automatically: every approver should only be able to see the entries they can, or already have, approved.