samba smb.conf

[smb_share]
path = /mnt/sdb/share
public = yes
only guest = yes
writable = yes
printable = no
force user = XXXX

[ZZZZ]
comment = YYYY's stuff
path = /mnt/sdb
valid users = YYYY
public = no
writable = yes
printable = no
create mask = 0765
directory mask = 0755

https://wiki.archlinux.org/index.php/samba#smb.conf