rooted_at+xpath queries require ./ prefix

[kpdecker]

Filing a bug for clarification on the behavior vs. the docs. All of the doc examples that use rooted_at and the xpath query seem to require the './' prefix to properly resolve, but this is not in the docs.

Filing this issue to clarify the intended behavior. (I can update the sections of the docs that I have seen this if the intended behavior is to require the ./ prefix)