Mattar assumed his current role in April 2021. The group’s brands include Holiday Inn, Holiday Inn Express, Crowne Plaza, voco, Hotel Indigo, Six Senses, InterContinental, Vignette Collection, and Staybridge Suites. In March 2024, the group announced a management agreement with the King Abdullah Financial District Management and Development Company to bring two luxury hotels to Riyadh in 2027, the Regent Riyadh KAFD and the InterContinental Riyadh KAFD. Mattar was previously a senior advisor for the Ministry of Tourism in Saudi Arabia and the CEO of the Ras Al Khaimah Tourism Development Authority.