所以我设法使工作分三部分进行。

1. 在“附加组件”标签上的产品数据元框中以多选形式显示全局附加组件
2. 保存自定义元字段
3. 将全局加载项添加到要显示在前端的加载项列表中

注意：我建议创建一个虚拟产品类别。分配全局加载项以显示在虚拟类别中的产品中，以防止它们在任何地方显示，因此仅当您将它们添加到元框时才显示。

/**
 * Add a custom field to the Add-ons meta panel
 */
function kia_add_custom_addons_fields() {

    global $product_object;

    if( ! $product_object instanceof WC_Product )  {
        return;
    }

    $global_addons = WC_Product_Addons_Groups::get_all_global_groups();

    ?>
    <div class="wc-pao-field-header">
        <p><strong><?php esc_html_e( 'Global Add-on Groups','your-text-domain' ); ?><?php echo wc_help_tip( __( 'Add a global group to this particular product','your-text-domain' ) ); ?></strong></p>
    </div>

    <div class="wc-pao-global-addons">

        <p class="form-field">
            <label for="global_addons"><?php _e( 'Apply Global Add-ons to this product','your-text-domain' ); ?></label>

        <?php

        // Generate some data for the select2 input.
        $product_add_ons = array_filter( (array) $product_object->get_meta( '_global_addons' ) );

            ?>

            <select id="global_addons" class="wc-enhanced-select" name="global_addons[]" multiple="multiple" style="width: 400px;" data-sortable="sortable" data-placeholder="<?php esc_attr_e( 'Search for a Global Add-on&hellip;','your-text-domain' ); ?>" >
            <?php
                foreach ( $global_addons as $add_on ) {
                    echo '<option value="' . esc_attr( $add_on['id'] ) . '"' . selected( in_array( $add_on['id'],$product_add_ons ),true,false ) . '>' . wp_kses_post( $add_on['name'] ) . '</option>';

                }
            ?>
            </select>

        </p>
    </div>
<?php
}
add_action( 'woocommerce_product_addons_panel_start','kia_add_custom_addons_fields' );


/**
 * Save the custom field data.
 *
 * @param obj $product WC_Product - the product object.
 */
function kia_save_custom_addons_fields( $product ) {

    // Layout.
    if ( ! empty( $_POST[ 'global_addons' ] ) ) {

        $meta = array_map( 'intval',(array) $_POST[ 'global_addons' ] );

        $product->add_meta_data( '_global_addons',$meta,true );
    }

}
add_action( 'woocommerce_admin_process_product_object','kia_save_custom_addons_fields' );


/**
 * Force the custom add-on into the product display.
 *
 * @param  array $product_addons
 * @param  int $post_id
 * @param  return array 
 */
function kia_add_global_product_addons( $product_addons,$post_id ) {

    global $product;

    if( ! is_admin() && $product instanceof WC_Product && $post_id === $product->get_id() ) {


        $meta = $product->get_meta( '_global_addons',true );

        if( ! empty( $meta ) ) {

            $args = array(
                'posts_per_page'   => -1,'post_type'        => 'global_product_addon','post_status'      => 'publish','suppress_filters' => true,'include' => $meta
            );

            $global_addons = get_posts( $args );

            if ( $global_addons ) {
                $new_addons = array();
                foreach ( $global_addons as $global_addon ) {
                    $new_addon = apply_filters( 'get_product_addons_fields',array_filter( (array) get_post_meta( $global_addon->ID,'_product_addons',true ) ),$global_addon->ID );
                    $new_addons = $new_addons + $test;
                }

                $product_addons = array_merge( $new_addons,$product_addons );

            }

        }
    }

    return $product_addons;
}
add_filter( 'get_product_addons_fields','kia_add_global_product_addons',10,2 );