Chewy key problem

Hi all,

Xml like so:

<a>
	<b>
		<desc>some text
		</desc>
		<bChild>
			<desc>some other text
			</desc>
		<bChild>
	</b>
	<b>
		<desc>some text
		</desc>
		<bChild>
			<desc>some other text
			</desc>
		<bChild>
		<bChild>
			<desc>maybe some more text
			</desc>
		<bChild>
	</b>
</a>

So b elements can have description children (desc), and so can their bChild
children.

I'm getting my butt kicked trying to build a key that matches on the
concatenated value of the (b/desc value) + any/all (bChild/desc) value(s).

The goal is to Meunchian group all the b elements on the concatenated value
of their desc and the desc values of however many bChild children there are.

I hope that is clear, and thanks for any help!

E