Example config for get_all_custom_field_meta()

config.php

<?php
$config = array(
	array(
		'name' => 'prefix_subtitle',
	),
	array(
		'name'       => 'prefix_content_row',
		'sub_fields' => array(
			array(
				'name' => 'css_classes',
			),
			array(
				'name' => 'background_color',
			),
			array(
				'name'       => 'columns',
				'sub_fields' => array(
					array(
						'name' => 'column',
					),
				),
			),
		),
	),
);