Two level PO Approval Workflow

Hi Experts,

I am new to sap workflow. I have a requirement to create a workflow for PO approval. The requirement is as follows

When the PO is created, the workflow will trigger and it will go for approval to first level approver ( get a new workflow in SBWP) and when the first level approver release the PO it will go to the second level approver.

I am using a copy of the standard workflow WS20000075. For me when a PO is created it will go for approval to the first approver but when the he release the PO it will not go to the second level approver.

For the start Event I am using Object Type : BUS2012 and Event of the Object  as RELEASESTEPCREATED. I use TS20000166 task and assign both the user in it.

Please see the below screen for your reference.

Start Event

for the first Activity

for Second activity

Please help me to resolve the Issue.

Thanks

Himadri