Complex sentence: Many members of AIP are also members of the National Association of Parliamentarians (NAP), and both organizations have worked together with joint NAP/AIP Chapters, collaboration on a Code of Ethics for Parliamentarians, and joint conferences.
Split into simpler sentences: Many members of AIP are also members of the National Association of Parliamentarians (NAP), and the two organization do work together. There are joint NAP/AIP Chapters, they collaborated on a Code of Ethics for Parliamentarians, and have joint conferences.