In case it could still be of interest: @ocoda/event-sourcing is a NestJS module that offers the basic functionality that @nestjs/cqrs provides, but also adds the necessary tools for storing and retrieving events (and snapshots). You get the option to choose one of the supported drivers for the persistence (e.g. Postgres or MariaDB if you're using want to use a relational database).

The documentation elaborates a bit more on how the library itself can be used to implement CQRS and Event Sourcing within NestJS.

Full disclosure: I'm the creator of the library.