All Schedulde Reports from Unified Reporter is saved in database where JasperReport Server is using.
You can not find any files in any of folders because report content is being saved in a folder and folder resides in repository.
(*) In JasperReports Server, folder path is URI in the repository, not disk path.
Take a look P14 of the following guide.
1.2 Overview of the Repository
The repository is a hierarchical structure of folders where JasperReports Server, administrators, and users store
resources for creating, running, and viewing reports. In its appearance and function, the repository resembles a
file system with a structure of folders containing files. However, the repository is actually implemented as a
database that is private to the server instance. As a result, it lacks a few of the functions of a file system.
How you can export report files from JasperReports Server
Some utility tools (such as js-export) become available with UIM package wasp_unified_reports_configurer.
This is native tools for JasperReports Server so that docs for these tools are available in the Jasper doc as follows.
Please find P137 for details.