After you create a Join View to flatten the XML, you can edit the column names that are exposed by the Join View.
Editing table and column names is a general Join View functionality and is not specifically designed to be used with XML. But given the default naming convention when using XML, it is a common scenario to rename columns to make testing simpler.
The following image shows the columns in the
Select Output Columns
The Alias column lets you override the name of the fields. Use this column to create shorter, more "friendly" names.
Include as Output Field
column lets you select which columns to expose to Table Pairs and Single Tables when the Join View is used.