Are you looking to get rid of the tiny arrow pointing downwards in DIVI WordPress theme?
You can do it fairly easily by adding this custom CSS on to your Divi panel

#top-menu .menu-item-has-children > a:first-child::after, .fullwidth-menu .menu-item-has-children > a:first-child::after, #et-secondary-nav .menu-item-has-children > a:first-child::after {
display: none;
}