Adding Pending Approver to a Report

We need to add the next approver to a Report. We are unable derive the next approver (to whom the requisition is not yet assigned for approval) for requisitions which are pending approval. We are able to derive the last approver and current approver details from FA_fusion_soainfra.wftask tables but unable to derive the next approver who is after the current approver in the approver list. Please let us know if this is an achievable solution.