Complex sentence: This opened a window of opportunity for Chanda Sahib who wanted to become Nawab of Arcot and joined the cause of Muzaffar Jung and began to conspire against the Nawab Anwaruddin Muhammed Khan in Arcot.
Split into simpler sentences: This opened a window of opportunity for Chanda Sahib, who wanted to become Nawab of Arcot. He joined the cause of Muzaffar Jung and began to conspire against the Nawab Anwaruddin Muhammed Khan in Arcot.