Scratching my head on this one and run out of URL combinations to try. I have a Flow that copies an email attchment into a DocLib folder, this works as expected:
The document is created in the '1-Registration' folder in the default DocLib. I now want to update the file properties but the SPS Action doesn't allow me to pick Site/Folder, it asks for Site/Library name! 
So my question is, how can I update the file properties of a document sitting in a folder within a library. Yes, I have tried every combination URL in the Library name field, but it will only accept a Library, not a folder within a library. I am thinking of creating a new 'Temporary' DocLib, creating the file there, updating the properties, then moving it to the correct '1 - Registration' library. However can anyone explain why the Create File screen asks for Site/Folder and the Update Properties action asks for Site/Library?