How to approach unpacking *condensed* CAN messages in Simulink?

I'm using Simulink for analysing a CAN bus, but i'm not sure how to approach unpack so-called condensed CAN messages. There is a block for unpacking normal CAN messages in the Vehicle Network Toolbox, but this doesn't apply in my case with condensed messages.

The image shows (albeit simplified) how the messages are composed. Byte 1 indicates in which context(rows) the message must be interpreted. Byte 2 and 3 are used for actual data; to configure settings or receive values of eg. analog inputs.

The CAN unpack block can separate the bytes in a CAN message, but doesn't account for their context. How can I best approach that? I've got the academic license, so I have access to (almost?) all toolboxes if necessary.