DenyGroups ftpusers

Match group sftpusers
  ChrootDirectory /backups/sftp/%u
  AuthorizedKeysFile /backups/sftp/%u/%h/.ssh/authorized_keys
  X11Forwarding no
  AllowTcpForwarding no
  
Match Group BCKviewer
  ChrootDirectory /vhome/%u
  AuthorizedKeysFile /vhome/%u/.ssh/authorized_keys
  ForceCommand internal-sftp
  AllowTcpForwarding no
  X11Forwarding no