The English translation (just using Google translate) of that link is below:
On 13 November 1918, four days after the overthrow of the monarchy, seized the assets of the House of Hohenzollern, the new government. The previous extensive property was placed under forced administration of the Prussian Ministry of Finance. A comparison should govern the difficult issue of future ownership. The difficult negotiations between the former royal family and the Prussian state lasted eight years.
Until 1925 two settlement proposals were submitted, both found no approval of the Prussian Landtag. A third was on 12 Was in October 1925 by the Prussian Minister of Finance Dr. Hermann Aschoff and chief representative of the former royal family, signed by Councillor Frederick mountain. But wanted to wait before the parliament for ratification until the outcome of the referendum on the "Law for the expropriation of princely fortune." The vote of 20 June 1926 took place while the votes required for adoption of the Law of 20 million, only 14.4 million, but was subsequently the royal house ready for further concessions, so that on 6 October 1926 amendment to the contract between the chief representative of the former Prussian royal family and the state government could be completed.
With the agreement, the state owns 75 locks with side plots and gardens. The royal family remained 39 buildings and land, including in Berlin, the palace of Emperor William I. and the Dutch Palace, in southern Germany the Hohenzollern castle, Burg Sonneck, Stolzenfels and Rheinstein Castle, also in Potsdam, the villas Ingenheim, Legnica and Alexander. Crown Prince Wilhelm and his wife Cecilia and their children and grandchildren was left the Potsdam Cecilienhof residence for life.
The former Hofkammergut of Hohenzollern was divided. 50 000 hectares of land remained the former royal family, the other half fell to the Prussian State. The cash compensation of Hohenzollern was set at 15 million marks.
The regalia (scepter, orb, Imperial Seal, imperial flag Reichhelm) who had previously left the royal palaces and gardens of the State loan went into the possession of the state, while the remaining crown jewels of the royal family.
Archive for the House of Hohenzollern was a joint management agreement. The holdings of the Hohenzollern Palace Museum Monbijou remained in the possession of the royal family. Your administration took over the state, the task was entrusted in 1927, the Palace Department.
In the turmoil of the Second World War, only a fraction of the Treaty on the property settlement awarded possession of the house of Hohenzollern to be rescued. The majority of the buildings and land, which remained the royal family were, as the magnificent palace on Unter den Linden with their precious equipment, were destroyed. The estate of the former royal family was mostly in East Germany and was at the end of the war as a dispossessed. So alone had the Thronlehn Oels in Silesia with 15 manors and Forestry published a volume of approximately 10 000 ha
Today, only the Hohenzollern castle is privately owned by the House of Hohenzollern. The land is completely lost.