Could you open local_root option

[chan15]

My FTP user account is chan, so I made a volume like /data/a/chan:/home/vsftpd/chan, it works perfectly, but I found out some of my client's code will use ../other to put files to relative up folder, so I need to make a volume like /data/a:/home/vsftpd/chan and set /data/a/chan as default folder when login ftp, and also they can go up folder to other folder, is it possible?