I use the code in
https://github.com/itf/org-export-with-files/blob/master/org-export-with-files.el
in order to define a new function that exports the current subtree to a
different folder, as well as create hard copies of the files linked in the
new directory and fixes the links in order to keep the links inside the
file working in the new directory.
It only works with PDF currently.

But in summary, I use:
(org-set-property
"EXPORT_FILE_NAME"
file-name)

To set a new file name,

and
(let*
  ((new-file-name (concat directory-name file-name)))
  (set-visited-file-name (concat new-file-name ".org"))

before exporting, in order to set a new directory, since the directory
comes from the directory of the current file, which can be set by "
set-visited-file-name" (remember to undo this afterwards).

On Fri, Sep 4, 2020 at 2:51 PM Uwe Brauer <oub@mat.ucm.es> wrote:

> >>> "NG" == Nicolas Goaziou <mail@nicolasgoaziou.fr> writes:
>
> > Hello,
> > Bastien <bzg@gnu.org> writes:
>
> >> There is none, that's indeed a backward compatibility issue.
>
> > Note that exporting to a different directory is called publishing.
>
> As you  wish, but my original question stands, how to I do this, which
> is the variable to be set, locally in the org file?
>
>