The Ecumenical Patriarch is the spiritual leader for all the Exarchates and regions of the Orthodox Church in the Diaspora. This includes the Greek Orthodox Archdiocese of America.
The Archbishop of America is the administrative and spiritual leader of all the Metropolises within the continental United States. This includes the Greek Orthodox Metropolis of Pittsburgh.
The Metropolitan of each Metropolis guides the spiritual life and administration of the parishes under his jurisdiction. The Metropolis of Pittsburgh includes 48 parishes in Pennsylvania, Ohio and West Virginia, along with five monastic communities.
The priest of the local parish receives his authority directly from the Metropolitan (bishop) of his region (Metropolis), and acts as the Metropolitans ambassador to the parish. Assignment and/or reassignment of the local priest is made by the Metropolis, not the parish.
For more information, well, you are already on our website...
For links to other Orthodox jurisdictions and Archdioceses, go to: http://www.goarch.org/en/resources/links/