I want to know how to specify the source data for one drive business.
Hello, and welcome to the forum @Juannieves!
If you mean you want to have Duplicati back up your OD4B cloud content to somewhere else, that isn’t natively supported.
I’m not familiar with One Drive for Business myself, but if you can get it exposed on your local machine as a mount point (drive letter, subfolder, etc.) then you could probably get Duplicati to back i up that way. However, it’s not an optimal solution and you’ll likely find that it uses a lot of bandwidth and, depending on your internet speeds, could be a bit slow.