SSHFS - Mount remote directory through gateway machine

1. Expose target target server ssh port with ssh local port forwarding
   $ ssh -C -N -L localhost:local_port:target:target_ssh_port gateway_user@gateway
2. Mount with sshfs through the port just exposed
   $ sshfs target_user@localhost:/target_directory /mount_point -o port=local_port

Example:

$ ssh -C -N -L localhost:22222:tap-machine:22 tapvpn@company-vpn-host.org

$ sshfs tap@localhost:~/work /mnt/work -o port=22222

Credit: Mounting Filesystems with SSH Forwarding Across a Gateway