Synthetics and APM integration

In the advanced options of synthetics there an option to choose APM service name. However few things are not clear like

  1. Let's say I have a service in APM running in two environments with the same name, to which environment the integration will happen. We don't have option to choose environment here.
  2. Under which header (Overview, Transactions, Errors etc) we can we see this synthetics data.