Hey Rick,
It’s not really built to work in two different places at once, but if it’s possible, you’d use this function: https://docs.generatepress.com/article/navigation-search/#use-navigation-search-in-secondary-navigation
However, you’d need to remove these lines:
remove_action( 'generate_inside_navigation', 'generate_navigation_search' );
remove_action( 'generate_inside_navigation', 'generate_mobile_menu_search_icon' );
remove_filter( 'wp_nav_menu_items', 'generate_menu_search_icon', 10, 2 );