Hi Florian,
this is a great question and idea, but unfortunately there is no OOTB functionality or configuration that will publish the URL groups in Team Center at the moment.
There is a way of adding extra nodes (vertexes) to the map by writing an EM extension, maybe we could look into that. I'll contact you directly - then we can talk about this (and the other things you wrote to me about ).
Can you check something for me: Do you have any information about the URL group in the transaction traces? I can't remember if this information is decorated to the transaction trace.
In 10.2 we added a feature to automatically create business transactions (BTs) from the URLs detected by the Browser Agent. Although this is not exactly the same thing, it might help you in your situation.
BR,
Stig