product-select.php

<?php
/**
 * @var \WPDesk\Forms\Field $field
 * @var string $name_prefix
 * @var string[] $value
 */

?>

<select class="wc-product-search" multiple="multiple" style="width: 50%;"
		id="<?php echo \esc_attr( $field->get_id() ); ?>"
		name="<?php echo \esc_attr( $name_prefix ); ?>[<?php echo \esc_attr( $field->get_name() ); ?>][]"
		data-placeholder="<?php \esc_attr_e( 'Search for a product&hellip;', 'wp-forms' ); ?>"
		data-action="woocommerce_json_search_products_and_variations">
	<?php
	foreach ( (array) $value as $product_id ) {
		$product = wc_get_product( $product_id );
		if ( is_object( $product ) ) {
			echo '<option value="' . \esc_attr( $product_id ) . '"' . selected(
				true,
				true,
				false
			) . '>' . wp_kses_post( $product->get_formatted_name() ) . '</option>';
		}
	}
	?>
</select>

<script type="text/javascript">
	jQuery(document.body).trigger('wc-enhanced-select-init');
</script>