process automation with single approver or group

Summary:

Hi,

We have a VBCS application that kick off the OPA process for approval. From VBCS screen depending on the transaction sometimes user may choose a single approver or a group that we configured in IDCS for approval and this information will be fed to OPA via start message. I'm using Build the list with names and expressions and I can choose user or group in the list of assignees.

How I can make the Approval activity work in both cases where OPA is invoked with single approver in the message or the IDCS group name in the message.