(1) one member from each public high school in the center's service region, elected by and from among the members of that high school board for a term determined by that high school board; and

(2) the superintendent or his or her designee of each supervisory union within the center's service region; and

(3) one member elected for a term of three years by and from among the school board of each sending district in the center's service region that does not have a public high school represented on the advisory board under subdivision (1) of this section; except, that if there are more than three such districts in the center's service area, the advisory board shall select three school boards to represent the interests of all such districts, shall rotate its selections among the districts, and shall stagger the expiration of initial terms; and

(4) one member of the board of each independent comprehensive high school within a service region, elected by the members of that board for a term determined by that board; and

(5) once constituted, the regional advisory board shall elect three additional members for terms of three years to represent the interests of employers or employees, provided that no two terms shall expire in any year.