Why does austria - hungary not want serbia to get bosnia?

Hey did not want freedom for serbia as serbia was an independent state all ready, they were not a part of the austro-hungarian empire 

what the black hand wanted was freedom for other nations and provinces that had a large percentage of serbians living in them. 

places like Bosnia which was part of the empire and had many serbs living there. 

what they wanted was freedom for all these places so that these places could be joined together with serbia to make a 'greater serbia' 

they got their wish at the end of the war with the creation of the country of yugoslavia, which brought together a number of places with serbian people living there (even if a massive minority) under one serbian flag