Except as otherwise provided in this section, any person appearing as a witness before any public official, department, board, bureau, commission, or agency, or any representative of a public official, department, board, bureau, commission, or agency, in any administrative or executive proceeding or investigation, public or private, if the witness so requests, shall be permitted to be accompanied, represented, and advised by an attorney, whose participation shall be limited to the protection of the rights of the witness, and who may not examine or cross-examine witnesses. The witness shall be advised of the right to counsel before the witness is interrogated. This section does not apply to proceedings before a grand jury or to an employee of an appointing authority, as defined in section 124.01 of the Revised Code, who appears only as a witness in an employment interview, investigation, or proceeding conducted by or for the appointing authority.