How do I import Purview Unified Audit Log data related to the use of the Audit Log into Sentinel?

Hello BM-HV​ 

There is no built‑in Microsoft Sentinel connector that ingests Purview Unified Audit Log search activity (i.e. who searched the audit log, when, and with what query).

To achieve your scenario, you must ingest the data manually via the Office 365 Management Activity API, then build analytics in Sentinel on top of it.

Kindly look at the response let by ​ Caleb_A_McDowell​  for more details on this.