Edit the Blackboard values for Behavior Tree run as a subtree

I am experimenting with Behavior Trees and Blackboards. I see that it is possible to run subtree’s inside a behavior tree using the Run Behavior task, which seems to be a good way to categorize and build AI logic that can be used for many AI actors.

My question is, how can I access the blackboard asset of the subtree in code? Normally, I would tell the AI Controller to use a particular BT and a particular BB. But when I have multiple of those, how do I access them later?

Also, if the subtree uses the same type of blackboard as the parent tree they seem to automatically share the same blackboard object because even if I don’t check “Instance Synced” on a particular value on the blackboard, they are the same for the subtree and the parent tree.

I couldn’t find any documentation on this, can anyone tell me what the workflow here is?

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