Nested group demo

nested1.php

<?php
add_filter( 'rwmb_meta_boxes', 'nested_groups_demo' );

function nested_groups_demo( $meta_boxes )
{
	// Meta Box
	$meta_boxes[] = array(
		'title' => __( 'Books', 'rwmb' ),

		'fields' => array(
			array(
				'id'     => 'authors',
				'name'   => __( 'Authors', 'rwmb' ),
				'type'   => 'group', // Group type
				'clone'  => true,

				// List of child fields
				'fields' => array(
					array(
						'name' => __( 'Full Name', 'rwmb' ),
						'id'   => 'name',
						'type' => 'group',

						'fields' => array(
							array(
								'id'   => 'first_name',
								'name' => __( 'First Name', 'rwmb' ),
								'type' => 'text',
							),
							array(
								'id'   => 'last_name',
								'name' => __( 'Last Name', 'rwmb' ),
								'type' => 'text',
							),
						),
					),
					array(
						'name' => __( 'Phone', 'rwmb' ),
						'id'   => 'phone',
						'type' => 'text',
						'size' => 10,
					),
					array(
						'name' => __( 'Email', 'rwmb' ),
						'id'   => 'email',
						'type' => 'email',
						'size' => 15,
					),
				),
			),
		),
	);

	return $meta_boxes;
}

nested2.php

<?php
$meta_boxes[] = array(
		'title'  => 'Multi-level nested groups',
		'fields' => array(
			array(
				'id'     => 'group4',
				'type'   => 'group',
				'clone'  => true,
				'fields' => array(
					// Normal field (cloned)
					array(
						'name'  => 'Text',
						'id'    => 'text4',
						'type'  => 'text',
						'clone' => true,
					),
					// Nested group level 2
					array(
						'name'   => 'Sub group',
						'id'     => 'group2',
						'type'   => 'group',
						'clone'  => true,
						'fields' => array(
							// Normal field (cloned)
							array(
								'name'  => 'Sub text',
								'id'    => 'text4',
								'type'  => 'text',
								'clone' => true,
							),
						),
					),
				),
			),
		),
	);