Accordeon Menu CK
Structure & Navigation
Menu Systems
https://extensions.joomla.org/extension/accordeon-menu-ck/
https://www.joomlack.fr/en/download-joomla-extensions/view_categories/5-accordeonmenu-ck
Sim
http://www.joomlack.fr/en/component/dms/view_document/54-documentation-accordeonmenu-ck