During the development process a Mambu database schema is required to be linked to the Jaspersoft Studio for the reports to be build with the correct data structure. This database is also useful for the developer to have some data to work with.
Our recommendation is to obtain a local clone of the database (schema and data) of one of your testing environments (such as sandbox) and work with it directly. We support this kind of operation, but note that only users with administration rights can perform it.
Check more details on how to obtain a database dump.