As the name suggests Privileged docs option under Document manager plug-in helps to create privileged folder, where we have an option to add members with 'Upload' privilege while creating the folder. And those people can upload files/documents to the specific folder in addition with accessing the documents within the folder. 

1. Go to Collaboration->Documents.
   

2. Click on ‘Privileged docs’ in the ‘Create’ drop-down.

3.  Provide folder name,  add members with "upload privilege" by selecting department and click on submit button.

• Again go to documents. Click the option ‘Privileged documents’. Select the newly created folder. and click ‘Add documents’.

• Select the mode to be ‘private’ and select the recipient users so the selected users can only have access over the document. Give the proper name and attach the file to be uploaded.( If you want to provide global access select the visibility as Public)