How to map two different xml messages into one xml message. all xml messages have repeating records. for example:

Source XML#1:
RepeatingTag1
-Field1
-Field2
-Field3

Source XML#2
RepeatingTag2
-Field1
-Field2
-Field3

Destination XML:
RepeatingTag1
-Field1
-Field2
-Field3
RepeatingTag2
-Field1
-Field2
-Field3