County courts (županijski sudovi) decide on appeals against municipal court rulings, but appeals against commercial court rulings are heard by the High Commercial Court of the Republic of Croatia (Visoki trgovački sud Republike Hrvatske). Appeals can be lodged with the court of first instance that made the ruling (municipal or commercial court, as described below).
More than one court/authority has been found which is competent for this legal instrument based on the information you provided. Below is the list: