The root text (below) clearly states that below the hub of the wheel is the hell realms (naraka). To the right and left of that are the animal and ghost realms. See all images for the Five Section Wheel of Life.
'Beneath the hub paint naraka, and on its two sides paint animals and hungry ghosts. Then on the top paint humans and gods.' (See Reinventing the Wheel).
At the top are the humans and gods realms. The Buddha also instructs to include all four continents that surround Mount Sumeru. This is rarely found with Himalayan art depictions although sometimes hinted at with some examples such as HAR #85113.
'in the middle is ...the king of mountains Sumeru. East Purvavideha; south Jambudvipa; west Aparagodaniya; north Uttarakuru; Deha and Videha; Chamara and Apachamara; Sata and Uttaramantrina; Kurava and Kaurava.' (Extracted from the long text known as the Thirty-seven Heap Mandala Offering Prayer written by Chogyal Pagpa, 1235-1280).
With Himalayan art it is far more common to separate the Wheel of Life topic into two parts. The first subject is the wheel itself, vertical and two dimensional, held in the hands and feet of the demon samsara. The second subject, often depicted with perspective and an attempt at three dimensionality, is mount sumeru surrounded by the four continents and islands. Only one painting example, the Ajanta mural, has been put forward with the suggestion that it follows the Wheel of Life format while including all four continents in clear segmented sections.
Jeff Watt [updated 6-2022]
Source Text: Mūlasarvāstivāda Vinaya Vibhanga: (translated from the Chinese version of the Sanskrit text)
'At the time the World-Honored One told Ananda, "The Great Maudgalyayana will not always be everywhere. This kind of phenomenon is truly rare. For this reason I command all bhikshus [monks] to paint a wheel of birth and death beneath the room at the gate of the temple.'
'At that time the various bhikshus did not know how to paint one. The World-Honored One told them: "Being careful of the proportions, draw an image of a circle. Place the hub in the middle and then place five spokes to represent the Five Paths. Beneath the hub paint naraka, and on its two sides paint animals and hungry ghosts. Then on the top paint humans and gods. In the path of humans make the four continents: [Purva]videha to the east, the Jambu continent [Jambudvipa] to the south, [Apara]godani to the west, the [Uttara]kuru continent [Uttarakurudvipa] to the north.'
'In the hub make a white circle and paint an image of the Buddha in the center. In front of the Buddha image paint three symbols. First make a pigeon to symbolize greed. Next make a snake to symbolize hatred. Last make a pig to symbolize delusion. Around the rim make the image of a wheel for carrying water. put on many water pails and draw images of sentient beings dead and alive: the live ones have their heads poking out of the pail, the dead ones have their feet poking out. Within each of the Five Paths make the respective symbols.'
(Reinventing the Wheel. Paintings of Rebirth in Medieval Buddhist Temples. Stephen F. Teiser. University of Washington Press, Seattle & London. 2006. Page 55).(The images below are only a selection of examples introducing the five sections and four continents. See all images for the Five Section Wheel of Life).