Hello There,
Please help in understanding the meaning of destination mapping.
If you are referring to destination mapping value then it depends on the partner i.e. in case of Google, this field will auto-populate and in others, you need to get this value from Partners but mostly it is the segment ID only.
If above is not in alignment with what you have asked for then please elaborate a bit more on this query and we will try to provide you with best possible solution.