The short answer to this is no.  Paperless for Mac and Paperless for Windows were not designed to share the same library files.

That being said, however, you should be able to do the following, albeit not seamlessly:

- open a Paperless library created on a Mac with Paperless for Windows

- open a Paperless library created on a Windows machine with Paperless for Mac

- import a Paperless library created on a Mac into Paperless for Windows

- import a Paperless library created on a Windows machine into Paperless for Mac

You will find that not all metadata, collections, smart collections and other properties of your library will transfer between Mac and Windows perfectly.  Again, the Paperless libraries, at least for version 2.0 are not designed to be cross platform.

Fortunately, the library structure for both Paperless for Mac and Paperless for Windows were designed in such a way that we will hopefully be able to allow some cross-platform library sharing in the future.  We will be looking at iCloud and other shared storage options, but we aren't yet in the planning stages for such cross-platform compatibility.