Backing up Structure saves the existing structures, their configuration, hierarchies and other Structure data. Structure backup does not save the issues themselves or other JIRA data - see Structure Backup, Restore and Migration.
To back up Structure:
Enter the name for the backup file. If you omit file extension, either .zip will be added to it.
You cannot specify directory for the backup file. Backup is always done to the export sub-directory under JIRA home.