How can we allow certain users to view critical fields while restricting access for others, all within the same application and read-only interface? What’s the best approach to achieve this?
Discussion posts and replies are publicly visible
On top of this (and this may not apply in your situation) I would consider if the real thing you are restricting access to the data OR if it's something else such as a user experience thing where different personas or situations benefit from a different UI experience.
I mention this as if it's the data that needs to be controlled I would also add in record level security to ensure you only show the data to the right people. It's another layer (you would still want to have dynamic UI elements) but can be critical in certain situations such as protected data (personal identifying and health data for example).
https://docs.appian.com/suite/help/24.4/record-level-security.html