A family of Microsoft relational database management systems designed for ease of use.
I rather doubt Microsoft Purview is up to the task but it's something you could investigate if you want.
On the desktop, I think one tool for the job could be Everything, from voidtools.com.
It is really fast and has the ability to set filters for specific searches; it will locate every accdb on a computer; Unfortunately, it's probably not going to work across an entire network, though.