Access From file manager

I want to access files like Scanned pdf books and documents from my file manager those are very important me to access whenever I wanted. How can I do that, if it possible let me know how to do. If not pls provide that feature. At first I used CamScanner it was very comfortable to access but now it has been banned in my country (India) so I switched to Adobe Scanner. but the problem is I can't rescan all off them.