How to create search indexes by path in Drupal 8?
I was able to resolve the issue by using the Views, not through the search indexes as I initially thought was the path for a solution.

Created a required field for the content-types that would be searched against. Let's call it Section for now, with the values of Employers and Employees. This will be used in the view to filter content by section. (Taxonomy terms can be used for this as well.)

Then created a view page for each section.



In the view, used Content for the row style with Search result highlighting input option, and sorted content by Search: Score (asc).

The real trick for this to work is enabling Search result highlighting input display mode and configuring it with the fields we want to be searched within.

Hope this helps who needs a similar solution in their projects.