You do not have a link list with a handle set to bmw-series-5-e34-1988-1996, or you do and it's empty. Go ahead and create a link list called BMW Series 5 E34 (1988 - 1996) on your Navigation page and populate that link list with links that point to collections, to see collections listed here. Make sure the link list also has a handle set to bmw-series-5-e34-1988-1996.