yiisoft/yii2 — pull request #5897 by otsec (2014-11-03 21:59:15+00:00)
Title: Added "submenu" property for "items" config in Menu widget

Implementation of https://github.com/yiisoft/yii2/issues/5681.

Allowing to set a specific submenu template will be very helpful for generating menu with 3-4 sub-levels.