The court trying any civil case may upon its own motion, and shall upon the motion of any party, require the exclusion of every witness. However, the following shall be exempt from the rule of this section as a matter of right: (i) each named party who is an individual; (ii) one officer or agent of each party that is a public or private corporation, partnership, association, governmental agency, or other entity; (iii) an attorney alleged in a habeas corpus proceeding to have acted ineffectively; and (iv) in an unlawful detainer action filed in general district court, a managing agent as defined in § 55.1-1200. Where expert witnesses are to testify in the case, the court may, at the request of all parties, allow one expert witness for each party to remain in the courtroom; however, in cases pertaining to the distribution of marital property pursuant to § 20-107.3 or the determination of child or spousal support pursuant to § 20-108.1, the court may, upon motion of any party, allow one expert witness for each party to remain in the courtroom throughout the hearing.