
Hi Fabio,
You can add HTML in your callback function as you want, so for example you can easily a wrapping div as follow:
function fabio_secondary_menu() {
?>
<div class="example-class">
<div class="tm-secondary-nav uk-container uk-container-center">
<?php
wp_nav_menu( array(
'theme_location' => has_nav_menu( 'secondary' ) ? 'secondary' : '',
'container' => false,
'beans_type' => 'navbar',
) );
?>
</div>
</div>
<?php
}
Note that I even moved the container in an HTML div in the example above which is not needed if you prefer to have it added in wp_nav_menu()
as you did in your code snippet.
Happy coding,

Wow, thank you Thierry. I wish you and the community an Happy New Year 2017.

Thanks Fabio, happy new year to you too 🙂