Complex sentence: However, in smaller countries, it could be the primary level of administrative division (Administrative divisions of Armenia, Administrative divisions of Azerbaijan), or, in Bulgaria, an administrative subdivision of a big city not related to the administrative division of the country.
Split into simpler sentences: However, in smaller countries, it could be the primary level of administrative division (Administrative divisions of Armenia, Administrative divisions of Azerbaijan). In Bulgaria, it is an administrative subdivision of a big city not related to the administrative division of the country.