§1. With the approval of the Apostolic See, several diocesan bishops can agree to establish a single tribunal of first instance for their dioceses in place of the diocesan tribunals mentioned in cann. 1419-1421. In this case, the group of bishops or a bishop they designate has all the powers which a diocesan bishop has over his own tribunal.
§2. The tribunals mentioned in §1 can be established either for any cases whatsoever or only for certain types of cases.
Source: Code of Canon Law (Vatican.va)