function zekadesign_print_scripts_styles() {
    if ( is_user_logged_in() ) 
    {
        // Print all loaded Scripts
	global $wp_scripts;
        echo "<b>Scripts</b><br>";
	foreach( $wp_scripts->queue as $script ) :
		echo $script . '  **  ';
	endforeach;
	 
	// Print all loaded Styles (CSS)
	global $wp_styles;
        echo "<b>Styles</b><br>";
	foreach( $wp_styles->queue as $style ) :
		echo $style . '  ||  ';
	endforeach;
    }
}
 
add_action( 'wp_print_scripts', 'zekadesign_print_scripts_styles' );

Taken from https://crunchify.com/how-to-print-all-loaded-java-scripts-and-css-stylesheets-handle-for-your-wordpress-blog/ and modified to include a check for logged in users.