descendant
An element matching other somewhere below this one. The result keeps other's match choice and this selector's scope. This selector must not carry a match choice itself: the ancestor is a bare predicate, so list.at(2).descendant(x) would otherwise search under every list. Narrow the ancestor with predicates instead, or pick among the results (list.descendant(x).at(2)).
Throws
when this selector has a match choice, or other has a scope different from this one.