Complex sentence: It follows the "Vijja Dhammaka" or Dhammakaya meditation, founded by Phramongkolthepmuni in the early 20th century, which teaches the reality of a True Self (the "Dhammakaya") in all beings, which is equated with Nirvana.
Split into simpler sentences: It follows the "Vijja Dhammaka" or Dhammakaya meditation, which was founded by Phramongkolthepmuni in the early 20th century. It teaches the reality of a True Self (the "Dhammakaya") in all beings, which is equated with Nirvana.