Help on displaying Folder and sub folder metadata

Hi,

We have multiple folders with sub folders to process documents. The service will move documents either success folder or failure folder based on document process status. 

I have a need to display the files present in failure folder/sub folders. I did the simple POC and seems stright foward but I need your help on few thisngs

1. I am able to display all files from a folder but not from sub folders. How can i fix it?

2.  I have gateway installed onpremise and reports are running on Power BI online. How ca we configure to display data after deploying report on Power BI service?

3. What is the best way to handle folder path when we have different enviroments such as dev, test and prod?

Thanks

Ravi Potturi