Create custom product details tabs within WooCommerce using an ACF (Advanced Custom Fields) Repeater field.

acf-fields.php

<?php
if( function_exists('acf_add_local_field_group') ):

acf_add_local_field_group(array (
	'key' => 'acf_product_options',
	'title' => 'Product Options',
	'fields' => array (
		array (
			'key' => 'acf_product_options_tabbedcontent_label',
			'label' => 'Tabbed Content',
			'name' => '',
			'type' => 'tab',
			'instructions' => '',
			'required' => 0,
			'conditional_logic' => 0,
			'wrapper' => array (
				'width' => '',
				'class' => '',
				'id' => '',
			),
			'placement' => 'top',
			'endpoint' => 0,
		),
		array (
			'key' => 'acf_product_options_tabbedcontent_tabs',
			'label' => 'Tabs',
			'name' => 'tabs',
			'type' => 'repeater',
			'instructions' => '',
			'required' => 0,
			'conditional_logic' => 0,
			'wrapper' => array (
				'width' => '',
				'class' => '',
				'id' => '',
			),
			'min' => '',
			'max' => '',
			'layout' => 'row',
			'button_label' => 'Add Tab',
			'sub_fields' => array (
				array (
					'key' => 'acf_product_options_tabbedcontent_tab_title',
					'label' => 'Tab Title',
					'name' => 'tab_title',
					'type' => 'text',
					'instructions' => '',
					'required' => 0,
					'conditional_logic' => 0,
					'wrapper' => array (
						'width' => '',
						'class' => '',
						'id' => '',
					),
					'default_value' => '',
					'placeholder' => '',
					'prepend' => '',
					'append' => '',
					'maxlength' => '',
					'readonly' => 0,
					'disabled' => 0,
				),
				array (
					'key' => 'acf_product_options_tabbedcontent_tab_content',
					'label' => 'Tab Content',
					'name' => 'tab_content',
					'type' => 'wysiwyg',
					'instructions' => '',
					'required' => 0,
					'conditional_logic' => 0,
					'wrapper' => array (
						'width' => '',
						'class' => '',
						'id' => '',
					),
					'default_value' => '',
					'tabs' => 'all',
					'toolbar' => 'full',
					'media_upload' => 1,
				),
			),
		),
	),
	'location' => array (
		array (
			array (
				'param' => 'post_type',
				'operator' => '==',
				'value' => 'product',
			),
		),
	),
	'menu_order' => 0,
	'position' => 'normal',
	'style' => 'default',
	'label_placement' => 'top',
	'instruction_placement' => 'label',
	'hide_on_screen' => '',
));

endif;