This happens ins the function wp_redirect_admin_locations()
, and there is no filter in that function to modify the values.
However, you can either just unhook that function and replace it your own function, or leave it as it is and add some additional shorthands in your own callback.
For the custom callback, use the filter 404_template
like in this example:
add_filter( '404_template', function( $template ) {
$request = trim( $_SERVER['REQUEST_URI'], "https://wordpress.stackexchange.com/" );
switch ( $request ) {
// German
case 'anmelden':
case 'einloggen':
// Spanish
case 'iniciar':
wp_redirect( wp_login_url() );
exit;
case 'dashboard':
wp_redirect( admin_url() );
exit;
}
return $template;
});