In the US Congress, a Legislative Director is appointed by all offices to overseas the monitoring of all legislature, and supported by the legislative assistants. They will manage pending legislation, conduct research into areas affected by it and draft the text while also being actively involved its development through recommendations and counsel. A Legislative Director may be assisted by Legislative Assistants or Legislative Coordinators.
In the West Wing, one of Josh Lyman's previous roles in government was as the Democratic Legislative Director.