Oracle Process Automation (OPA): How to append the array types

Hi All,I'm trying to append the payload array object from multiple human tasks into a final human task payload (in data association).

Was working in Gen2 Process cloud, but not finding the option to append in OPA gen3.

Once I import the process, I see the data association mapping is changed to directly mapping.

How can we achieve this functionality without redesign?

Thanks,

Ashwin