Is there a way to access files/documents stored in a NAS storage from within a p

Do mean files on a file system that are not part of Appian collaboration? The best way is to access them using SCP via the File Transfer plugin. They can be then downloaded into Appian collaboration and exposed via links on the form.
There are other options but in essence Appian cannot just "access a folder on my computer".

Mike: Are you suggesting to use Remote Transfer Smart Services Plugin?