In standard SAP, system will determine the nature of the taxes whether it is a domestic tax or export tax on the basis of the country of plant from where goods will be shipped (Source) and the the country of the Ship to party , where goods will be delivered (Destination) .
Now if Country of Plant and Ship to is same, system will determine domestic taxes as goods are not moving out from the country.
and if country of Plant and Ship to are different, system will determine export taxes as goods are moving out from the country.
Br
Kanishk