Hello @Atos A.
It may be a little helpful to Monitor a third-party service as a separate service
Atos - You might try adding the third party service as a custom device, so that when Dynatrace identifies the certain IP address you tell it what it's looking it. If you're only looking for DEM clicks then yes, you found what you were looking for in the third party components and as far as I'm aware your answer to yourself is accurate.
I think I found the answer, this is registered as a metric, split up between 1st and 3rd party.
So in other words you can only see how many times your app got clicks on Facebook, but you can not relate this to any session or useraction.