I honestly dont think there is any way to do this. You would not normally connect two Codecs together.
MINI only has HDMI presentation in and HDMI to display out. The USB C is only used for used pass-through when connected to a laptop (use as a webcam).
- What are you intending on outputting from the MINI? Do you just need to output same content to three different displays?
- If you want to output FAR END and Presentation from the from a CODEC you could use something like the Room Kit plus or Room Kit
- If you want want the flexibility of the CODEC Pro and a wide angle camera you would probable need a third party camera and mics connected to the codec pro
- If you want the all in one MIC/Speaker all in one you could also use the Room Kit (not mini)
The short of the answer is that these two units aren't meant to work together. Would need to understand what you are looking to achieve to provide some additional guidance.