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

function bp_groups_filter_activity_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 groups of user.
	$groups = groups_get_user_groups( $user_id );
	if ( empty( $groups['groups'] ) ) {
		$groups = array( 'groups' => 0 );
	}

	// Should we show all items regardless of sitewide visibility?
	$show_hidden = array();
	if ( ! empty( $user_id ) && ( $user_id !== bp_loggedin_user_id() ) ) {
		$show_hidden = array(
			'column' => 'hide_sitewide',
			'value'  => 0
		);
	}

	$retval = array(
		'relation' => 'AND',
		array(
			'relation' => 'AND',
			array(
				'column' => 'component',
				'value'  => buddypress()->groups->id
			),
			array(
				'column'  => 'item_id',
				'compare' => 'IN',
				'value'   => (array) $groups['groups']
			),
		),
		$show_hidden,

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

	return $retval;
}