Members

ALL RANKS (EXCEPT EAGLE) BOARD OF REVIEW: 

The Board of Review consists of three to six members of the Troop Committee. The Troop Chairperson typically acts as the chairperson of the Board of Review. The Scout and parents have no part in selecting any board of review members. Relatives or guardians may not serve as members of a Scout's Board of Review. Unit leaders (Scoutmaster, Assistant Scoutmasters) may not participate in a Board of Review.

EAGLE BOARD OF REVIEW:

The Boy Scouts of America has placed the Eagle Scout board of review in the hands of either the troop, district, or council committee responsible for advancement. The local council will decide which method or methods may be used within its units. For the rank of Eagle, the Board of Review consists of three to six members drawn from Scouting and the community. The members of the Board of Review are selected by the unit, district, or council, depending on the council guidelines. At least one member of the District Advancement Committee must be a member of the Board of Review for Eagle, and normally serves as chairperson of the Board of Review. Unit leaders from the Scout's unit, relatives, or guardians may not serve as members of a Scout's Board of Review for Eagle. 

A Board of Review for Eagle may contain members of the community who are not registered Scouters; however, they should be knowledgeable of the principles of Scouting. For example, a representative from a chartering organization, an adult Eagle Scout (even if not currently registered), or a religious leader are frequently asked to assist with an Eagle Board of Review. As a general rule, no more than one member of an Eagle Board should be associated with the Scout's unit.

Resource: https://boyscouttrail.com/boardofreview.asp#TenderQ