Is there a way to extract the array for a specified id with the set::class utiliy? I can't figure out the XPath.

I.E. I would like to extract the array where the id = 1

[Document] => Array
        (
            [0] => Array
                (
                    [id] => 1
                    [filename] => 1.txt
                )

            [1] => Array
                (
                    [id] => 2
                    [filename] => 2.txt
                )

            [2] => Array
                (
                    [id] => 3
                    [filename] => 3.txt
                )


        )