Nested Subnav mobile

Dear Community,

i use the 'beans_type' => 'sidenav' for mobile Overlay-Menus. It works finaly with one Submenu. But if i tried a Sub-Sub-Menu it doesn´t work. Only the first level of parent-pages works like a accordion. The nested subnav is not hide.

the structur is:

Parent 1

• Subnav Item 1
  • SubSubnav Item 1
    • SubSubnav Item 2
• Subnav Item 2
  • SubSubnav Item 1
    • SubSubnav Item 2 Parent 2
• Subnav Item 1
  • SubSubnav Item 1
    • SubSubnav Item 2

• Subnav Item 2

  • SubSubnav Item 1
    • SubSubnav Item 2

  Has anybody a idea? Thanks.