Complex sentence: King Amanullah was also a Musahiban through his mother, sister of King Nadir Khan's sister, who was also the great-granddaughter of Wazir Akbar Khan, son of Dost Mohammed Khan.
Split into simpler sentences: King Amanullah was also a Musahiban through his mother, sister of King Nadir Khan. She was also the great-granddaughter of Wazir Akbar Khan, son of Dost Mohammed Khan.