D&C 107

After learning that the Quorum of the Twelve Apostles is equal in power and authority to the First Presidency and the Seventy are equal in authority to the Twelve, the Savior teaches -

"The Twelve are a Traveling Presiding High Council, to officiate in the name of the Lord, under the direction of the Presidency of the Church, agreeable to the institution of heaven; to build up the church, and regulate all the affairs of the same in all nations, first unto the Gentiles and secondly unto the Jews.
34 The Seventy are to act in the name of the Lord, under the direction of the Twelve or the traveling high council, in building up the church and regulating all the affairs of the same in all nations, first unto the Gentiles and then to the Jews..."  (Doctrine and Covenants | Section 107:33 - 34)

Every  member and leader has a file leader.