How do we transition using router service if we have to mount the engine at multiple locations?

Say suppose if my engine’s package.json name is my-engine and I want to mount this as eng-a and eng-b . Then how would I write a this.router.transitionTo("<what-should-be-here>.my-route-1.sub-route") so as to make it work in both the mount points.

It depends on where you mount your engine. If you say:

Router.map(function () {
  this.mount('my-engine', { as: 'eng-a' });
});  

Then it’s transitionTo('eng-a');

But if you say:

Router.map(function () {
  this.route('admin', function() {
    this.mount('my-engine', { as: 'eng-a' });
  });
});  

Then it’s transitionTo('admin.eng-a');

How do we make the transition inside the engine using router service of the app irrespective of the as param that we provide in the mount method?