Looping Through Sub-Folders

Is there an easy way to loop through a directory of subfolders and do the same thing inside each subfolder? The activities inside each subfolder would include reading PDFs and producing outputs.

If not in UiPath, is there a simple script I could use or write in another place? Does anyone have any suggestions? Thanks

Simplest way of doing it by using

What would this return to me?

Array of string.
With all pdf files are stored in this particular directory or sub directory.