The local Church as a sacramental organism, as the Gift of God in Christ, is not part or member of a wider universal organism.
She is the Church.
Objectively, as the Body of Christ, the Church is always identical to herself in space and time.
In time, because she is always the people of God gathered to proclaim the death of the Lord and to confess His resurrection.
In space, because in each local Church the fullness of gifts is given, the whole Truth is announced, the whole Christ is present, who is "yesterday and today and forever the same."
In her sacramental and hierarchical order the Church reveals and conveys to men the fullness of Christ into which they must grow (cf. Eph. 4:13).
Fr. Alexander Schemann in "St. Vladimir's Theological Quarterly" in 1960