From the Basic search, select "More Search Options" (advanced search mode)
On the first row, enter search terms in first box and select appropriate field (e.g. lead paragraph)
On second row, enter < editorial* > and select field = "Section"
Open the "Subject" facet (click the rightward triangle)
Scroll down to "Content types" and click on the "+" to display additional options.
Scroll down and click on "Editorials" to add to your search
Close the "Subject" facet (click the down triangle)
Enter your search terms and any other parameters.
Document Type = Editorial
Document Type = "Opinion" or "Editorial"