Complex sentence: Chaim Tzvi Teitelbaum married Bracha Sima Halberstam, a sister of Chaya Freidel Halberstam, who was the wife of Ben Zion Halberstam.
Split into simpler sentences: Chaim Tzvi Teitelbaum married Bracha Sima Halberstam. She was a sister of Chaya Freidel Halberstam, the wife of Ben Zion Halberstam.