how to configure this type of menu

Question

So I sort of have this kind of menu dynamically coded in WordPress:

I am somewhere in the ballpark with the code in header.php:

Toggle navigation

            <!-- If the menu (WP Admin area) is not set, then the "menu_class" is applied to "container". In other words, it overwrites the "container-class". -->
            <?php
                wp_nav_menu(array(

                    'menu'      => 'topnav',
                    'container' => 'false'
                ));
            ?>

        </div><!-- container -->
    </div><!-- navbar -->
<div class="navbar-wrapper">
    <div class="navbar navbar-inverse navbar-fixed-top" role="navigation">
        <div class="container">
            <div class="navbar-header">
                <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="navbar-collapse">
                    <span class="sr-only">Toggle navigation</span>
                    <span class="icon-bar"></span>
                    <span class="icon-bar"></span>
                    <span class="icon-bar"></span>
                </button>

                <a class="navbar-brand" href="/"><img src="<?php bloginfo('stylesheet_directory'); ?>/assets/img/Logo.png" alt="UpAbility"></a>
            </div><!-- navbar-header -->

            <!-- If the menu (WP Admin area) is not set, then the "menu_class" is applied to "container". In other words, it overwrites the "container-class". -->
            <?php
                wp_nav_menu(array(

                    'theme_location'    => 'primary',
                    'container'         => 'nav',
                    'container_class'   => 'navbar-collapse collapse',
                    'menu_class'        => 'nav navbar-nav navbar-right'
                ));
            ?>

        </div><!-- container -->
    </div><!-- navbar -->
</div>

In functions.php:

<?php
/**
 * UpAbility functions and definitions
 *
 * @link https://developer.wordpress.org/themes/basics/theme-functions/
 *
 * @package UpAbility
 */

if ( ! function_exists( 'upability_setup' ) ) :
/**
 * Sets up theme defaults and registers support for various WordPress features.
 *
 * Note that this function is hooked into the after_setup_theme hook, which
 * runs before the init hook. The init hook is too late for some features, such
 * as indicating support for post thumbnails.
 */
function upability_setup() {
    /*
     * Make theme available for translation.
     * Translations can be filed in the /languages/ directory.
     * If you're building a theme based on UpAbility, use a find and replace
     * to change 'upability' to the name of your theme in all the template files.
     */
    load_theme_textdomain( 'upability', get_template_directory() . '/languages' );

    // Add default posts and comments RSS feed links to head.
    add_theme_support( 'automatic-feed-links' );

    /*
     * Let WordPress manage the document title.
     * By adding theme support, we declare that this theme does not use a
     * hard-coded <title> tag in the document head, and expect WordPress to
     * provide it for us.
     */
    add_theme_support( 'title-tag' );

    /*
     * Enable support for Post Thumbnails on posts and pages.
     *
     * @link https://developer.wordpress.org/themes/functionality/featured-images-post-thumbnails/
     */
    add_theme_support( 'post-thumbnails' );

    // This theme uses wp_nav_menu() in one location.
    register_nav_menus( array(
        'menu-1' => esc_html__( 'Primary', 'upability' ),
    ) );

    /*
     * Switch default core markup for search form, comment form, and comments
     * to output valid HTML5.
     */
    add_theme_support( 'html5', array(
        'search-form',
        'comment-form',
        'comment-list',
        'gallery',
        'caption',
    ) );

    // Set up the WordPress core custom background feature.
    add_theme_support( 'custom-background', apply_filters( 'upability_custom_background_args', array(
        'default-color' => 'ffffff',
        'default-image' => '',
    ) ) );

    // Add theme support for selective refresh for widgets.
    add_theme_support( 'customize-selective-refresh-widgets' );
}
endif;
add_action( 'after_setup_theme', 'upability_setup' );

function upability_register_custom_menu() {
    register_nav_menu('topnav', __('Top Nav'));
}
add_action('init', 'upability_register_custom_menu');

So in my wp-admin I have this:

[![enter image description here][2]][2]

but I am not sure where to go from here. I did read this documentation:

https://codex.wordpress.org/Appearance_Menus_Screen

but it does not bring me to an answer. For example, here is what has happened:

As you can see the BLOG and LOGIN are in both nav bars. How do I add the right menu options for the other nav bar?