Wordpress: Function to make an array of elements from an specific taxonomy even at a second level of hierarchy

get_taxonomy_data.php

<?php
function rc_get_categories_data()
{

    $categories_data = [];

    $taxonomy     = 'category'; //change this with the taxonomy you want
    $orderby      = 'name';
    $show_count   = 0;      
    $pad_counts   = 0;     
    $hierarchical = 1;      
    $title        = '';
    $empty        = 0;

    $args = array(
        'taxonomy'     => $taxonomy,
        'orderby'      => $orderby,
        'show_count'   => $show_count,
        'pad_counts'   => $pad_counts,
        'hierarchical' => $hierarchical,
        'title_li'     => $title,
        'hide_empty'   => $empty
    );
    $all_categories = get_categories($args);

    foreach ($all_categories as $category) {

        if ($category->category_parent == 0) {
            $category_id = $category->term_id;

            $args2 = array(
                'taxonomy'     => $taxonomy,
                'child_of'     => 0,
                'parent'       => $category_id,
                'orderby'      => $orderby,
                'show_count'   => $show_count,
                'pad_counts'   => $pad_counts,
                'hierarchical' => $hierarchical,
                'title_li'     => $title,
                'hide_empty'   => $empty
            );
            $sub_cats = get_categories($args2);

            $categories_data[$category->name] = ['name' => $category->name, 'slug' => $category->slug, 'sub-categories' => []];
            if ($sub_cats) {
                foreach ($sub_cats as $sub_category) {
                    $categories_data[$category->name]['sub-categories'][$sub_category->name] = ['name' => $sub_category->name, "slug" => $sub_category->slug];
                }
            }
        }
    }

    return $categories_data;
}

$categories_data = rc_get_categories_data();

The output: