Hi,
Buddhism: the dharmakaya, the sambhogakaya, he nirmanakaya.
The Buddha is defined by three bodies of enlightenment, the so-called trikaya of classical Mahayana theory. These include the dharmakaya, the body of ultimate reality; the sambhogakaya, the body of joy; and the nirmanakaya, the Buddha’s conditioned, human body of flesh and blood.
Interestingly, the trinity of Chinese Buddhism is described in almost the same way as the trinity of Christendom:
“The Three are all included in one substantial essence. The three are the same as one; not one, and yet not different; without parts or composition. When regarded as one, the three persons are spoken of as the Perfect One (Tathagata). (New Catholic Encyclopedia)
There is no real difference [between the three persons of the trinity in Buddhism]; they are manifestations, different aspects of the same unchanging substance.”
The formulation of the trinity of Chinese Buddhism had no connection with the Bible or Christendom.
Hinduism: Brama, Vishnu, Siva.
The Hindu trinity is composed of Brahma the Creator, Vishnu the Preserver, and Siva the Destroyer. Together, the three composed the one god Brahm. Brahma is the supreme god of the Hindus, but actually he is shown little consideration, there are possibly only two temples devoted to him. Vishnu, the second person of the Hindu trinity, receives the worship of millions. Siva, the third person of the trinity, is figured with a rope for strangling evildoers, with a necklace of human skulls, with earrings of serpents and with the sacred river Ganges on his head. Numerous temples are erected for his honor and worship.
Religious triads began in Babylon: the moon (for the god Sin), the sun (for Shamash), and a star (for Ishtar). (this constitute one of many triads).
Cheers
The connection between the Christian Trinity and these other "triads," seems tenuous at best, both historically and conceptually.
Christianity certainly incorporates concepts from paganism though, so maybe it's possible? The whole fundamental notion of the need for animal and human sacrifice to avert the judgment of a god is pagan. Jesus as described in the Gospels shares many similarities with mythological pagan heroes.