Hello Raghavendra Manohar,
In order to provide an exact answer, we would be needing additional information from your end like probably a screenshot of your domain model structure containing the Employee and LeaveRequest entity and the Microflow which you had build which failed to work.
Assuming you would have proceeded in the below mentioned steps, probably you can try the following and let us know if it worked:
General Assumtion : You have two entities in your Domain Model namely Employee and LeaveRequest and that they both are having a 1-* association i.e. One Employee can have many LeaveRequests. See sample screenshot for reference
Finally use the Total Leaves Attribute for your purpose. Hope this helps. Incase it didn’t, request you to kindly share the screenshot of your domain models and explain your usecase in an ellaborated way :)