You can change the root directory in vsftp as you wish..
If you enable chroot_local_user=YES, it will restrict local users to their home directories.
Some times you may want to change your root form home directory to other directory.
To change the home directory from user home directory to other directory add following lines in your vsftpd.conf (/etc/vsftpd.conf).
anonymous_enable=YES
anon_root=/home/user/dir (here you can set the directory as you wish)
Following is my vsftpd.conf
listen=YES
anonymous_enable=YES
local_enable=NO
write_enable=YES
dirmessage_enable=YES
use_localtime=YES
xferlog_enable=YES
connect_from_port_20=YES
secure_chroot_dir=/var/run/vsftpd/empty
pam_service_name=vsftpd
rsa_cert_file=/etc/ssl/private/vsftpd.pem
anon_root=/home/abc/mydir
-Sany