Inject a child provider to the parent in angular?

Question

I would like to add a feature in a parent component using the activated child's provider.

I've got two children like so :

Child1.module.ts

  providers: [
    { provide: Service,  useClass: Service1},
  ],

Child2.module.ts

  providers: [
    { provide: Service,  useClass: Service2},
  ],

Now, in the parent module, i want to provide Service1 or Service2 depending on which child is activated, maybe with a provide:Service, useFactory: (route: ActivatedRoute) or something ?

Edit :

Here a quick picture of the idea :

Thanks !