Complex sentence: On 1 January 2015, the hotel has been taken over by Hilton Hotels & Resorts and will receive an extension building in the near future It is be used for the brand "Hilton" while the extension will be a "Hilton Garden Inn" when completed.
Split into simpler sentences: On 1 January 2015, the hotel has been taken over by Hilton Hotels & Resorts and will receive an extension building in the near future. While the existing building is used for the brand "Hilton" the extension will be a "Hilton Garden Inn" when completed.