Reproduction steps:
1. Open column menu
2. Using arrow keys, go to Filter menu item.
3. Hit right arrow to open Filter submenu
4. Tab through filter submenu
5. Hit escape.
Expected behaviour: Filter submenu closes and focus returns to the parent column menu
Actual behaviour: Both filter and column menu are closed.
Snippet: http://dojo.telerik.com/@gearoidj/iqiwUCEp
This is an issue for accessibility users - there doesn't seem to be a way to return to the parent filter menu using the keyboard without closing all menus and reopening them.
There is one way for it to occur, and that is to use the mouse to place the focus on the Filter menu background - in this case hitting escape will close the Filter menu and focus will be returned to the parent column menu. However this is impractical for an accessibility user who is relying solely on keyboard navigation.
An example of where this (mostly) works is on the Columns submenu - the user can use the left arrow key or Escape to close the child menu or alternatively keep tabbing and they will eventually return to the parent menu (though if they do tab within the child menu, hitting Escape will close both the child and parent menus).