Obtain all subtrees in value
<p>Given "a.b.c.d.e" I want to obtain all subtrees, efficiently, e.g. "b.c.d.e" and "c.d.e", but not "a.d.e" or "b.c.d".</p>

<p>Real world situation:</p>

<p>I have foo.bar.baz.example.com and I want all possible subdomain trees.</p>
