If you are a party to proceedings you are entitled to give evidence before the court at hearing or call witnesses in support of your case. Each witness who is not an expert witness is questioned by the party that called them, cross-examined by any other party to the case if they choose to do so, and sometimes re-examined by the party who called them to clarify or resolve any matters arising from the cross-examination.
In the ERD Court hearings are presided over by a Judge, a Commissioner or a Judge and Commissioners together. The role of the judicial officer presiding over the hearing is to ensure that it is conducted fairly and according to law. That role includes the power to decide whether a witness may be permitted to give the evidence or whether a document can be received as evidence. If you have any questions that relate to the hearing process you should ask the judicial officer.