Hi yes, in that example, listing_selector is the parent element (container). It would be type: Element. It is not meant to scrape data; the actual scrapers are all child elements under it.
Using the "offshore-energy" example, here's a sitemap with a parent selectors and child scrapers.You will need to change the startUrl:
{"_id":"offshore","startUrl":["https:// secret offshore-energy website"],"selectors":[{"id":"Exhibitor selectors","type":"SelectorElement","parentSelectors":["_root"],"selector":"div.exh_box_inner","multiple":true,"delay":0},{"id":"Company","type":"SelectorText","parentSelectors":["Exhibitor selectors"],"selector":"span.exh_item_name","multiple":false,"regex":"","delay":0},{"id":"Desc","type":"SelectorText","parentSelectors":["Exhibitor selectors"],"selector":"span.exh_item_desc","multiple":false,"regex":"","delay":0},{"id":"Stand","type":"SelectorText","parentSelectors":["Exhibitor selectors"],"selector":"div:nth-of-type(1) span.exh_item_info_output","multiple":false,"regex":"","delay":0}]}