You can define that the user is able to upload documents to the Document Inbox (that is available in the Control Center). The user can then link these documents to a record.
To configure the Document Inbox and linking contained documents to records:
Define the DocumentInbox Web Configuration parameter, >> DocumentInbox. This parameter controls, whether the Document Inbox is displayed and the document types that can be added.
If you want the user to be able to edit data (e. g. specifying a file name, entering a description) when they link a document with a record, define an Edit control in the D3 info area containing the desired fields .
If you assign Filename as Function to a field, the file's name is automatically entered into this field.