How can I add user-specific files and content for each user as side-administrator?
And how can I be sure that only the user I've added the content for can see it?
User A --> A_invoice_07/15.pdf and A_invoice_08/15.pdf
User B --> B_invoice_07/15.pdf and B_invoice_08/15.pdf
So User A should only see his invoices and the same with User B.