[thelist] PHP - get one directory from a path?

[Stephen Rider]

Hi --

I'm trying to figure out a straightforward way to set a PHP variable  
to a particular directory in a path.

For example:  I have http://www.example.com/main/something/inner/ 
index.php
The path can change, though.  Specifically, the directory "something"  
is arbitrary -- the script could be running in http://www.example.com/ 
main/whatever/inner/ and so forth.

When the script runs, I want to set a variable to = "something", or  
whatever that directory name happens to be.

I know how to get the last directory name using dirname() and such,  
but I can't figure out how to get the directory two levels up....

Any ideas?  Thanks in advance!

Stephen Rider