hugo/docs/content/en/functions/intersect.md

title	linktitle	description	date	publishdate	lastmod	categories	menu	keywords	signature	workson	hugoversion	relatedfuncs	deprecated	aliases
intersect	intersect	Returns the common elements of two arrays or slices, in the same order as the first array.	2017-02-01	2017-02-01	2017-02-01	functions	docs parent functions	collections intersect union complement symdiff	intersect SET1 SET2				false

A useful example is to use it as AND filters when combined with where:

AND filter in where query

{{ $pages := where .Site.RegularPages "Type" "not in" (slice "page" "about") }}
{{ $pages := $pages | union (where .Site.RegularPages "Params.pinned" true) }}
{{ $pages := $pages | intersect (where .Site.RegularPages "Params.images" "!=" nil) }}

The above fetches regular pages not of page or about type unless they are pinned. And finally, we exclude all pages with no images set in Page params.

See union for OR.