ssh command has the useful '-J' option which allows you to connect via a proxy host. Very useful for hosts which are not directly reachable from the current network you are on.
Since '-J' corresponds to the ProxyJump directive, you can achive the same goal with sshfs like this:
sshfs hidden-host.example.org:/some/directory/ ~/mountpoint/ -o ProxyJump=proxy.example.org
this is very useful.