Download files from different folders


I'm new to Shiny.
I'm trying to develop a small Shiny application able to download files stored in different folders and to add them in a single data.frame.
I found scripts downloading several files but only from one single folder.

I'm not asking for a solution (but if you have one, it is perfect :slight_smile:), but rather a strategy, some commands or links that can help me to get one file in a folder then another one in another folder and do on.

Thanks in advance for advices.
Have a nice day,