Short answer: It does not come from any one Purva.

Explanation:

• In the Shwetambar tradition, the Kalpasutra is a later compilation traditionally attributed to Acharya Bhadrabahu. It draws on earlier teachings that were preserved through Dṛṣṭivāda (the 12th Aṅga, which contained the 14 Purvas), but it is not traced to a specific, single Purva.
• In the Digambar tradition, the Kalpasutra is not accepted as a canonical text, so no Purva-origin is assigned.