Query: Process is started with User who can upload document, the document can be downloaded in the reviewer task pages, however if the user doesn’t upload the document then the reviewer task pages can see upload document

Query: Process is started with User who can upload document, the document can be downloaded in the reviewer task pages, however if the user doesn’t upload the document then the reviewer task pages can see upload document.
When we try to implement this, its giving us the error saying two same variable cant be used.

Can anyone has implemented similar?