Restrict product visibility in WooCommerce to a specific user role

index.php

<?php
/**
 * Limit Product Visibility
 * @wordpress-plugin
 * Plugin Name:       Limit Product Visibility
 * Description:       A WooCommerce plugin to limit product visibility to administrators and a user role called Reps.
 * Version:           1.0.0
 * Requires at least: 5.2
 * Requires PHP:      7.2
 * Author:            Jesse Conner
 *
 * @package Limit Product Availability
 */

/**
 * Allows for products that can only be viewed by specific user roles.
 *
 * @since 1.0.0
 */
class LimitProductVisibility {

    private const META_KEY = 'limit_product_visibility';

	/**
	 * Instantiate the hooks and filters of our class
	 *
	 * @return void
	 * @since 1.0.0
	 */
	public function __construct() {

		add_action( 'init', array( $this, 'create_role' ), 11 ); // Creates the required roles and capabilities.
		add_action( 'woocommerce_product_options_general_product_data', array(
			$this,
			'product_settings'
		) ); // Add the visibility settings to products.
		add_action( 'woocommerce_process_product_meta', array(
			$this,
			'save_fields'
		), 10, 2 ); // Save the product visibility settings.
		add_filter( 'woocommerce_product_is_visible', array(
			$this,
			'product_invisible'
		) ); // Hide product from listings if it is hidden from normal customers.
        
	}

	/**
	 * Creates the required roles and capabilities
	 *
	 * @return void
	 * @since 1.0.0
	 */
	public function create_role() {

		add_role(
			'rep',
			'Rep',
			array(
				'read'           => true,
				'see_restricted' => true,
			),
		);

		$role = get_role( 'administrator' );

		// Add a new capability.
		$role->add_cap( 'see_restricted' );
	}

	/**
	 * Add the visibility settings to products
	 *
	 * @return void
	 * @since 1.0.0
	 */
	public function product_settings() {

		$limited = get_post_meta( get_the_ID(), self::META_KEY, true );

		?>
        <div class="option_group">
			<?php

			woocommerce_wp_select(
				array(
					'id'            => self::META_KEY,
					'label'         => 'Restrict access to:',
					'value'         => $limited,
					'options'       => array(
						''     => 'Not Restricted',
						'Reps' => 'Reps',
					),
					'wrapper_class' => 'form-field-wide',
				)
			);

			wp_nonce_field( 'restrict-access' );
			?>

        </div>
		<?php
	}

	/**
	 * Save the product visibility settings
	 *
	 * @param int $id The id of the post to apply the meta to.
	 *
	 * @return void
	 * @since 1.0.0
	 */
	public function save_fields( $id ) {

		if ( isset( $_POST[self::META_KEY] ) && check_admin_referer( 'restrict-access' ) ) {

			$role = sanitize_meta( self::META_KEY, wp_unslash( $_POST[self::META_KEY] ), 'post', 'product' );

		} else {
			return;
		}

		update_post_meta( $id, self::META_KEY, esc_attr( $role ) );
	}

	/**
	 * Hide product from listings if it is hidden from normal customers
	 *
	 * @return boolean Whether to hide the product or not.
	 * @since 1.0.0
	 */
	public function product_invisible() {
		$restricted = get_post_meta( get_the_ID(), self::META_KEY, true );

		if ( ! $restricted ) {

			return true;
		}

		return current_user_can( 'see_restricted' );
	}
}

// Make sure WooCommerce is active before instantiating the plugin.
if ( in_array( 'woocommerce/woocommerce.php', apply_filters( 'active_plugins', get_option( 'active_plugins' ) ), true ) ) {
	new LimitProductVisibility();
}