how to remove an UDA from Manage Items savedSearch that was previously added there via Page Composer

Summary:

Unable to remove an UDA from predefined Application Default Search criteria on Manage Items, this field was previously to that Manage Items page via a sandbox using Page Composer tool. We just want to remove that field from the list of search fields now. We want to add a newly created attribute in place of that. The currently added field is from a multi row AG while the new one that we have created belongs to a single row AG. The attribute name is 'Equipment Number', attached screenshot as well.

When I am inside a Sandbox with Page Composer tool and I want to remove the default available field Equipment Number from Manage Items Application Default saved search, this was previously added here using a Page Composer Sandbox only.