Use XPath/XQuery to do this. Refer to the examples page for an example on how to do this.
Return all descendants of node which match the given spec.
Refer to domQuery for more information on how to import and use this function.
The parent node under which to search
Node specification, as accepted by fontoxml-dom-utils' createNodeFilter.
Whether to continue the search under matching nodes Defaults to true, meaning all matches are returned.