Where is Vanguard stock held?

I've heard that The Vanguard Group, Inc has an interesting structure, as described by Investopedia:

The company is owned by its funds. The company’s different funds are then owned by the shareholders. Thus, the shareholders are the true owners of Vanguard.

I'm curious how this works and more importantly – how is this validated?

I looked at SEC filings and when I looked up reports of fund investments I didn't see any funds owning The Vanguard Group, Inc.

For example, lets look at the Vanguard Explorer Fund Investor Shares (VEXPX)

SEC Document: [NPORT-P] Monthly Portfolio Investments Report (2022-04-01 00:00:00)

Am I missing something? (Completely possible – I'm no pro)

I don't see how the company is owned by the funds – am I looking in the wrong place or how is this Validated?