Identifying some parts of Query Plan in SQL Server
===

I have recently encoutered a problem I have hard time working aournd. I have to tune a rather nasty query that extensively uses - in many forms and on several layers - XML. The problem is that while it is easy to spot the slow part of the whole query - Table Valued Function [XML Reader] - it is rather hard to map it to any specific part of the query. The properties does not indicate on which XML column does this particular object work and I'm really puzzled why is that. Generally it is relatively easy to map object to a part to a query but these XML objects are giving me a pause.

Thanks in advance.