Dear SAP Community,
I have created several complex in reports in testsystem based on available and custom databases.
Is there a possibility to transport or export/import them from Test-Tenant to Productive-Tenant or do I have to create them manually again?
You don't have to recreate the reports in your Production tenant again. Instead you can download the report metadata as XML file from test system and upload them in your production system. This works for all the custom reports which are created by Key User. This can be done from the common tasks view under Business Analytics work center.
Below is the help center link which explains on which obejcts the upload download is possible along with the steps: