; selects all the 'item' elements that have an 'olist' parent (which is not root)
; and that are in the same document as the context node
;
; Abbreviated XPath: //olist/item
; Full XPath: /descendant::olist/child::item

(define tree 
'(doc (olist (item "1")) (item "2") (nested (olist (item "3"))))
 )

; Low-level:
((node-join 
    (node-closure (ntype?? 'olist))
    (select-kids (ntype?? 'item)))
 tree)

; SXPath:
((sxpath `(// olist item))
 tree)

==>
((item "1") (item "3"))