Thunderbolt™ 2 Dock can connect to a Thunderbolt™ 3 port using an adapter from Apple:
Using this "Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter", you could connect a 2016 MacBook Pro to Thunderbolt™ 2 Dock.
- Cables and adapters not sold by Apple are not supported.
- Bandwidth will be limited to the Thunderbolt™ 2 standard.
- If you use the first Thunderbolt™ Dock, bandwidth will be limited to standard Thunderbolt speeds.