RH2017 - Excluding topics from search

In the responsive html5 online help we have the following structure:

Plans chapter
- topic A
- topic B
- topic C

New Plans chapter
- topic A
- topic B
- topic C

The Plans chapter entails all help topics of the legacy module of the application. This co-exists with the new application module.

The New Plans chapter holds the help topics for the latest development.

The same functionality is available in the legacy application and the new application at the moment. Eventually the older functionality will be phased out.

The requirement is that when the users search for topic A, it should ideally only fetch the topic A from the New Plans chapter. How can we achieve this?

If I apply Exclude from Search for Plans chapter > topic A, would the search automatically pick topic A from new Plans chapter? That should be good then.

Any thoughts?