You can repeat on the Columns to get the names.
Repeater XPath: Document_0.Output{/Rowsets/Rowset/Columns/Column}
Link editor to get column name XPath: Repeater_0.Output{/Column/@Name} or
Repeater_0.Item{/Column/@Name} depending on your version
Then in the same loop get the columns value.
Link editor to get column value XPath:
Document_0.Output{/Rowsets/Rowset/Row[1]/*[#Repeater_0.CurrentItem#]}
Regards,
Christian