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:
Verify that the user account that performs this procedure is a site collection administrator.
On the Settings menu for the site collection, click Site Settings.
On the Site Settings page, in the Site Collection Administration section, click Search Query Rules.
- Manage query rules in SharePoint Server
- Manage query rules in SharePoint Online