BenQ PD3220U with 2014 MacBook Pro Retina (USB hub question)
If you have another system (PC or Mac) and this 2014 MacBook Pro, you can have a DisplayPort KVM switch to have both systems share the monitor and keyboard/ mouse/ other USB devices.  With the DisplayPort KVM switch, you don't need to have a Thunderbolt 2-to-3 converter.  And you also can get extra USB sharing ports at the same time.
Just carefully to select the right DisplayPort-to-Type-C active converter for the connection between the KVM switch video out to the Type-C monitor.
We tested and recommended CAC-1557 for the cable  and UDP-12AP for the KVM switch.