The eighth chapter of the third book sets the scene at the end of a cosmic night: Vishnu, in the form that lies in the ocean of the womb of the universe, rests on the serpent Ananta. A lotus pushes up from his navel and fills the dark with light. Inside it Brahma appears, and because he can see nothing he looks about him, and from that looking he acquires four faces. He wonders aloud who he is and what the lotus is, and climbs down into its stem to find where it grows from, without success. He returns to the flower and sits in meditation; a hundred years of the gods pass before he sees Vishnu lying on the serpent. Only then does the wish to create arise in him. Chapter 20 continues the story of his creation. This is the origin most Indians know from calendar art.
Commentators in the line of Chaitanya name the reclining form Padmanabha, the lotus-navelled, and set it inside a scheme of three Vishnus: the great Vishnu who breathes out the universes, the one who lies in each universe's womb-ocean and gives birth to Brahma, and the one who lies in the ocean of milk within each. The story of the lotus is unchanged; the framework is sectarian.
What is different here:
Adds the three-Vishnu hierarchy, which is commentary and should not be presented as Purana text.