bp_users_filter_activity_following_scope( array $retval = array(), array $filter = array() )

function bp_users_filter_activity_following_scope( $retval = array(), $filter = array() ) {
	// Determine the user_id.
	if ( ! empty( $filter['user_id'] ) ) {
		$user_id = $filter['user_id'];
	} else {
		$user_id = bp_displayed_user_id()
			? bp_displayed_user_id()
			: bp_loggedin_user_id();
	}

	// Determine following of user.
	$following_ids = bp_get_following( array(
		'user_id' => $user_id,
	) );
	if ( empty( $following_ids ) ) {
		$following_ids = array( 0 );
	}

	$retval = array(
		'relation' => 'AND',
		array(
			'column'  => 'user_id',
			'compare' => 'IN',
			'value'   => (array) $following_ids,
		),

		// we should only be able to view sitewide activity content for those the user
		// is following.
		array(
			'column' => 'hide_sitewide',
			'value'  => 0,
		),

		// overrides.
		'override' => array(
			'filter'      => array(
				'user_id' => 0,
			),
			'show_hidden' => true,
		),
	);

	return $retval;
}