So far, I found there are some interesting ways to search in global structure:
As part of a process to generate FHIR XML bundles from HL7 messages, I have a subtransform transforming segments of an MDM_T02 message into a section of XML (EnsLib.EDI.XML.Document). So far this has worked well although I've encountered strange behaviour when making use of an xmlns attribute, whereby the attribute's name is duplicated despite the schema and DTL editor displaying it correctly.