Export to XML format is not yet available in the NetSuite User Interface.
A work-around is to use Web Services to generate a list of records in XML by reading the Web Services request/response from a getList operation.
Prerequisite: Familiarity with SuiteTalk/Web Services.
1. Send a Web Service getList request then open the response log for that request.
2. Navigate to Setup > Integration > Web Services Usage Log.
Note: Set the From field if the logs do not display.
3. On the list, select the getList operation and click on the view link on the Response column for that log. This will open/download an XML file containing the response/result of the Web Service request (which is a listing of records for the particular record type in XML).