This can greatly add to the time required for the hearings and is not to be desired. Although any party can request information, the written request must go through the Faculty Senate Administrative Secretary who coordinates the hearings. You do not have the right to examine documents that you would normally not see. Similarly, you are not entitled to read the peer or chair evaluations of other people who have been up for promotion, etc. However, you can request that the Panel obtain and review those evaluations or other documents in light of your allegations.
Every attempt is made to preserve privacy and confidentiality.
Although the hearings are confidential, let's face it, it's going to leak out that you have a grievance. You and the others involved will be gathering witnesses, data, etc. People will find out. Protection against reprisal. Traditionally, the Provost has taken a very dim view of any attempt to interfere with or to attempt reprisal against anyone involved in the grievance process.