Hi,
Late reply though I hope it can help others.
Here is what you can do, you can store the request node or content in a variable (custom property) in your virtual service. You can use an example code
//NodeValue can be the xpath of the XML in request. The code below will get the node value from request
def requestCustomerName = requestBody.getNodeValue("//*:name")
//The code below will create a new custom property in your virtual service - customPropertyName (you can change it to a sensible name) and will store the request content in it.
requestContext.mockService.setPropertyValue('customPropertyName',requestCustomerName)
//and then finally, you can call that custom property in your response like below.
<ns3:name>${#MockService#customPropertyName}</ns3:name>
I hope it helps