Complex sentence: At the national level, people elect a bicameral legislature, the Parliament of Pakistan, which consists of a directly elected National Assembly (a lower house) and Senate (upper house), whose members are chosen by elected provincial legislators.
Split into simpler sentences: At the national level, the people of Pakistan elect a bicameral legislature, the Parliament of Pakistan. The parliament consists of a lower house called the National Assembly, which is elected directly, and an upper house called the Senate, whose members are chosen by elected provincial legislators.