After searching the way to get some inspiration, i decided to realize the following think:
For all the self-made code, I use one module for the whole application and for all the external things, bundled with external plugins and services, I take a different module. This means: pne module for each "service-plugin bundle" (like google API & angular-google-maps plugin)
So I can switch the module, if the external service does not work, etc.
Looking at my example in the question this means:
Application part A: the map and all the map-specific things (set new marker, draw circle, etc) are insight a map-module. If I decide to use open street map instead of google maps i will plug in an new maps module
Application part A and B: this is my "main" app module with different controllers.