Hi Harika,
two possible reason
1. you are not completing the user task, after supervisor 1 apporoves , you have to complete task
2. if you are doing step 1 correctly then In your workflow go to
supervisor 2 task and check its target user microflow ,add a debugger and check which user it is returning , because these target users shall receive the task after it is approved or completed by supervisor1
Good luck!