Community Builder can be localized / translated to other languages using CB Language plugins.
Once a CB Language plugin is installed (using the CB Plugin Management installer), your Community Builder frontend and backend views will display messages in the specific language. The CB Language plugin will be automatically activated based on the language settings of Joomla. So, if Joomla backend is set to German and the CB German Language plugin is installed, you should be able to see CB related backend areas in the German language.
CB GroupJive and CBSubs also make use of CB Language plugins for translation purposes.
If you do not find your language listed on the official language forge areas, then consider volunteering for the mamnagement position by contacting the CB Team and expressing your interest.