2016 – Search Query Rules not showing in Central Admin

You can manage the search query rules at different levels in a SharePoint Server farm.

Site collection search query rules can be managed at Site collection by site collection administrator.

To manage query rules for a site collection:

  1. Verify that the user account that performs this procedure is a site collection administrator.

  2. On the Settings menu for the site collection, click Site Settings.

  3. On the Site Settings page, in the Site Collection Administration section, click Search Query Rules.

official documentations:

  1. Manage query rules in SharePoint Server
  2. Manage query rules in SharePoint Online