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

function your_prefix_register_meta_boxes( $meta_boxes ) {
    $prefix = '';

    $meta_boxes[] = array (
        'title' => esc_html__( 'Group', 'text-domain' ),
        'id' => 'group',
        'post_types' => array(
            0 => 'post',
        ),
        'context' => 'normal',
        'priority' => 'high',
        'fields' => array(
            array (
                'id' => $prefix . 'group',
                'type' => 'group',
                'name' => esc_html__( 'Group', 'text-domain' ),
                'fields' => array(
                    array (
                        'id' => $prefix . 'slider',
                        'type' => 'slider',
                        'name' => esc_html__( 'Slider', 'text-domain' ),
                        'std' => 16,
                        'clone' => 1,
                        'clone_default' => 1,
                    ),
                    array (
                        'id' => $prefix . 'button_group',
                        'name' => esc_html__( 'Button Group', 'text-domain' ),
                        'type' => 'button_group',
                        'std' => array(
                            0 => '3',
                            1 => '4',
                        ),
                        'options' => array(
                            1 => esc_html__( '1', 'text-domain' ),
                            2 => esc_html__( '2', 'text-domain' ),
                            3 => esc_html__( '3', 'text-domain' ),
                            4 => esc_html__( '4', 'text-domain' ),
                        ),
                        'clone' => 1,
                        'inline' => 1,
                        'multiple' => 1,
                        'clone_default' => 1,
                    ),
                    array (
                        'id' => $prefix . 'checkbox',
                        'name' => esc_html__( 'Checkbox', 'text-domain' ),
                        'type' => 'checkbox',
                        'desc' => esc_html__( 'Default Description', 'text-domain' ),
                        'std' => 1,
                    ),
                ),
                'clone' => 1,
                'default_state' => 'expanded',
                'clone_default' => 1,
                'collapsible' => true,
            ),
        ),
    );

    return $meta_boxes;
}