It is not possible to have CORE2 with both ESP32 and RPi at the same time. Trying to connect them at the same time may damage devices.
The hardware connector on CORE2 board could be suited to only one of the devices.
The ESP32 is attached on top of the CORE2, while RPi can be attached only on bottom side of CORE2.
If you have CORE2 with ESP32, connector is soldered on top side, while for RPi it should be on bottom side.
To connect RPi to your CORE2, you will have to connect wires appropriately.
The movie that you linked, shows CORE2 with ESP32. On the robot there is also Nvidia Jetson Nano, but there is no visible connection between CORE2 and Jetson.
I think that only author of the video can explain all the connections used.