Complex sentence: He was raised under the personal supervision of the seventh Lubavitcher Rebbe, Menachem Mendel Schneerson, the Halberstam family's ties to the Rebbe include his father, who worked as a butler and personal manager to the Rebbe.
Split into simpler sentences: He was raised under the personal supervision of the seventh Lubavitcher Rebbe, Menachem Mendel Schneerson. The Halberstam family had ties to the Rebbe as Ari's father worked as a butler and personal manager to the Rebbe.