Answer

In Jain tradition, Kshetrapal Bhomiyaji is revered as a guardian deity or protector of the temple/pilgrimage area, especially at Sammed Shikharji. The Jain tradition of kshetrapalas refers to deities who protect land or temple precincts, and they are commonly grouped as yoginīs, bhairavas, and vīras. ( jainpedia.org)

Explanation

The exact historical origin of Bhomiyaji is not presented in Jain sources as a single fixed, universally accepted biography. Instead, he appears mainly in devotional and pilgrimage tradition. At Sammed Shikharji, he is especially honored as the protector of the sacred hill and of pilgrims visiting the tirth. ( jainpedia.org)

A Jain pilgrimage source on Sammed Shikharji also mentions that, alongside the Jinalayas, temples for the ruling deities including Shri Bhomiyaji were established there. This shows that his worship became part of the living temple tradition of the tirth. ( jainknowledge.com)

Spiritual Understanding

In Jain practice, such deities are not equivalent to a Tirthankar. They are understood as protective devs who guard the sacred place and support devotees in a worldly, protective role. Their worship is therefore connected with protection, श्रद्धा, and reverence for the tirth, not with liberation itself. ( jainpedia.org)

Takeaway

So, in simple words: Bhomiyaji is the well-known kshetrapal of Sammed Shikharji, honored as a protector deity in Jain pilgrimage tradition. His history is mostly traditional and devotional, rather than a detailed scriptural biography. ( jainpedia.org)