Another example I came across today, "list all packages which are installed from bullseye-backports" (originally using ?narrow, but it's not needed). I was surprised that ?installed was listed under the "PACKAGE PATTERNS" heading in the manpage.
$ aptitude search '?any-version(?installed ?origin(Backports))' | wc -l 10 $ apt list '?any-version(?installed ?origin(Backports))' | wc -l 252
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