Property Transfer with xpath of element based on child element

Not sure how you are using it exactly. However, it is very easy to process the same from groovy as shown below:

/**
 * This script process the given xml string
 * and allows user to pass the known values (name as Hulk) and
 * retrieve the unknown(id)
 * */

def searchData = { data, element, siblingElement, siblingElementValue -> 
    def slurper = new XmlSlurper().parseText(data)    
    slurper.'**'.find{ it.name() == siblingElement && it == siblingElementValue }.parent()."$element".text()
}
//Pass xml string here.
log.info searchData(xml, 'id', 'name', 'Hulk')

The above script can used in two different ways:

1. as script assertion for same test stepSo, you can just change
   

   log.info searchData(xml, 'id', 'name', 'Hulk')

   to

   log.info searchData(context.response, 'id', 'name', 'Hulk')

2. a separate groovy script test stepyou need to get the response into xml variable to be able to use the above script.

NOTE: it should work for both namespace present and not.