List all custom taxonomy categories (parent and child) and their content

content-page-faq.php

<?php
$categories = get_categories(array(
  'orderby' => 'name',
  'parent' => 0,
  'taxonomy' => 'faqs_category'
));
?>

                   <?php

foreach($categories as $category) { ?>

                    <?php
  echo $category->name;
  $terms = get_terms(array(
    'taxonomy' => 'faqs_category',
    'hide_empty' => false,
    'parent' => $category->term_id
  )); ?>

                    <?php
  foreach($terms as $term) {
    $args = array(
      'post_type' => 'faq',
      'tax_query' => array(
        array(
          'taxonomy' => 'faqs_category',
          'field' => 'slug',
          'terms' => $term->slug
        )
      )
    );
    echo $term->name;
    $query = new WP_Query($args);

    // Start the Loop

    while ($query->have_posts()):
      $query->the_post(); ?>
                    <p><?php
      echo the_title(); ?></p>
                    <p><?php
      echo the_content(); ?></p>

                    <?php
    endwhile;
  } ?>


                <?php
} ?>