When in-site search is enabled, the search query will return results from all viewable subpages in the site. By default, the contents in all non-hidden subpages - including "Don't show in navigation" subpages - are available for search.
In some cases, not all viewable subpages contain relevant information. Follow the steps below to control which subpages are included in the search query results.
To show / hide subpage from in-search query result:
Click the target subpage from the left pane navigation;
Click Edit on the subpage;
Uncheck/check the Show content in search results box to hide/show, as preferred;
Click on Publish for the changes to apply to your site.