Study the four operas of Richard Wagner's tetralogy, Der Ring des Nibelungen otherwise known as "The Ring of the Nibelungen" or Ring Cycle: Das Rheingold (The Rheingold), Die Walküre (The Valkyrie), Siegfried, and Götterdämmerung, which translates as "Twilight of the Gods." Die Walküre will answer your questions more directly, but its important to watch the series from the beginning.
After watching these works, you can study the Gnostic Radio lectures on the operas on our website. I have referenced the course below.
These works will give you a very clear understanding of the attributes of God and His different parts on the Tree of Life, from the Father, Son and Holy Spirit, to the Innermost, Buddhi and Human Soul, the three types of soul in Kabbalah, and more. To answer your last question, yes, Dharmakaya, Sambhogakaya, and Nirmanakaya are Buddhist terms for Father, Son, and Holy Spirit.
Joyful in hope, suffering in tribulation, be thou constant in thy prayer.
Benedictis, qui venit in nomine Domini. Osanna in excelsis.
"Blessed is he who comes in the name of the Lord. Hosanna in the highest!"