It fully supports nesting of scripts across the whole filesystem hierarchy traveling appropiately
"down" and "up" running any relevant scripts it finds.
If you cd from /foo/bar/baz to /foo/quux/biff, the following scripts are run in this order:
1) bash_leave for /foo/bar/baz
2) bash_leave for /foo/bar
3) bash_enter for /foo/quux
4) bash_enter for /foo/quux/biff