if you have installed webEdition into the root directory (mine is /var/www) the backups should be here:
if you have trouble with the java uploader, you can manually upload your backups into the we_backup/data directory and then restore the backup via backend.
i have created myself a VirtualBox test-Webserver with lighttpd and PDT+Xdebug where you can easily setup a webEdition test-environment.
if you use linux/macOS you can either upload your files via FTP or even easier, via scp ssh.
scp weBackup_2014_01_28__11_13_28.xml.gz firstname.lastname@example.org:/var/www/webEdition/we_backup/data/
i had trouble with the java: