<?php
use Microsoft\Graph\Beta\GraphServiceClient;
use Microsoft\Graph\Beta\Generated\RoleManagement\Directory\RoleDefinitions\RoleDefinitionsRequestBuilderGetRequestConfiguration;
$graphServiceClient = new GraphServiceClient($tokenRequestContext, $scopes);
$requestConfiguration = new RoleDefinitionsRequestBuilderGetRequestConfiguration();
$queryParameters = RoleDefinitionsRequestBuilderGetRequestConfiguration::createQueryParameters();
$queryParameters->filter = "isPrivileged eq true";
$requestConfiguration->queryParameters = $queryParameters;
$result = $graphServiceClient->roleManagement()->directory()->roleDefinitions()->get($requestConfiguration)->wait();