Belgian visting Shanghai and Hong Kong

I hold a belgian passport and planning to visit both Shanghai and Hong Kong.
Due to airline fares I have two possible scenarios:
1. scenario 1: Belgium-Shanghai (stay 3 days), Shanghai-Hong Kong, Hong Kong-Shanghai (stay again 3 days) and then fly home (Shanghai-Belgium)
Am I eligible for the transit visum for both Shanghai parts or only for the first Shanghai part?
2. Scenario 2: Belgium-Shanghai (stay 6 days), Shanghai-Hong kong, Hong Kong- Belgium
I guess for this I am eligible for the transit visum?
Thanks