Prorated Salary with Multiple Salary Structure Assignment on Payroll Creation

Hi,

I have a simple scenario where an employee is being promoted in mid of the month, and I assigned the employee a new salary structure from that specific day.

Now what I want is, upon payroll creation, the system should cater all the salary structures assigned to that employee for that payroll period.

But unfortunately system is not behaving like this.

Can some of guys explain regarding this?