ESS WDA Leave Application - Multiple level approval

Scenario: Leave template is customized for multiple level approval. Leave is approved by first level approver(status is reset to 'SEND') and waiting for second level approval.

Meanwhile the employee changes the leave request and submits for approval again. How to subject the workflow to first level approver again? My understanding is that since the standard is designed for single level approval, there is no effect on workflow( change event) when a leave is modified when the leave is not fully approved. Any suggestion to overcome this issue?

Version EHP5 with WDA(NWBC).

Karthik.