Add submenu using the bootstrap wp_nav_menu

You will need to write a custom menu walker.

See this code for the walker. (Or do a search for “Bootstrap Menu Walker”.)

Then use:

    wp_nav_menu( array(
      'menu' => 'header',
      'menu_class' => 'nav nav-pills',
      'container' => 'nav',
      'container_class' => $classes,
      'fallback_cb' => false,
      'depth' => 2,
      'walker' => new Bootstrap_Walker_Menu_Nav(),
      'theme_location' => 'header',
      'echo' => false,
      ));