Multiple domains and subdomains (laravel 5)

My site is running with multiple subdomains on domain exa.com for example, now I need to set up another domain is exa1.com. So How can I update my route file to implement it?

Route::group(
    array(
        'domain' => '{business_slug}.exa.com',
        'middleware' => 'verify_domain'
    ), function() {
       Route::get('', [
          'as' => 'index',
          'uses' => 'HomeController@index'
       ]);

       Route::get('user', [
          'as' => 'user.index',
          'middleware' => 'auth',
          'uses' => 'UserController@index'
       ]);

       ...
});

via Chebli Mohamed