selector - nested uls

selector - nested uls

I have a div let's call it 'myDiv'
In it there are nested uls.
the first ul has 3 lis that represent the main menu
in those 3 lis there are a lot of nested uls (sub-menu, and sub-sub-menues....)
When I click a deep nested li, I want to remove all the content of the 2 other lis, but not the li that I am digging in.

what I tried removes the whole content inside all the main lis, including the one I am in.
  1. $('#myDiv>ul').find('ul').remove();