Philippines
The Philippines has a bicameral legislature: the Senate and the House of Representatives. The senators are elected nationwide at-large as one "district," with the twelve candidates with the most votes winning the twelve seats contested every election.
In the House of Representatives, four-fifths of its members are elected via first past the post in single member districts, while the remaining one-fifth is elected via a party-list system. There are currently 229 legislative districts in the country, each electing one congressman to the House of Representatives.
From 1916 to 1935, senators were also elected via districts, with eleven districts electing two senators, while the two senators in the twelfth district were appointed by the American governor-general.
While most legislators are elected via geographical districts, they represent their constituents; party-list representatives' constituents is the sector they represent, while the senators' constituency is the entire nation.
Read more about this topic: List Of Electoral Districts By Nation