Add the following snippet of code in your theme to the location where you would like the menu’s to be displayed.
<?php if ( is_user_logged_in() ): wp_nav_menu( array( 'menu' => 'Loggedin' ) ); else: wp_nav_menu( array( 'theme_location' => 'primary' ) ); endif; ?>
Basically, what the code above does, it checks if the user is logged-in and then displays the LoggedIn menu, you may replace LoggedIn with your menu name.
If the user is not logged-in we display the primary menu.
Image Credits: Photo by Isis França on Unsplash.