An Overtime rule allows users to either bank their overtime hours or have them paid out. It does not allow the user to manually decide which overtime hours can be considered for banking and which for pay out for the same Timesheet period.

Scenario:
Company A has users entering time on a weekly basis. They have a daily overtime rule that accredits users overtime if they work more than 8 hours. They have the option to either bank the extra hours or get them paid out. User B has accumulated 10 hours of overtime for a specific TimeSheet period and would like to bank 4 hours and get the remaining 6 hours paid out. This is not possible, since you can either bank the hours for a TimeSheet period or get them paid out.

Workaround:
In this scenario the only workaround would be to manually add selected hours to the Time Off In Lieu time off type and have the rest banked. Lets assume that User B has entered time on the Timesheet as listed below:

Monday          Tuesday          Wednesday          Thursday          Friday

   10                  10                    10                      10                 10

As per this Timesheet, the user is eligible for a total of 10 hours of overtime, assuming that the hours per day for user B is 8. Now user B would like to bank 4 hours and get the remaining 6 hours paid out. This can be achieved if the user adds a Time Off on the Timesheet and selects the type as 'Time Off In Lieu'. Instead of taking any hours the user needs to enter (-)4. A negative value adds to the existing balance. Thus the user is actually banking the 4 hours against the respective time off type. So the user has to manually edit the time entries on the timesheet to ensure that only 6 hours are being considered for overtime. The timesheet would look like this:

Monday          Tuesday          Wednesday          Thursday          Friday
    8                    8                     10                     10                  10  

And now click on 'Add Time Off' to add a row for Time Off in Lieu:

Time Off In Lieu (Remaining X Hours) -4

This will ensure that for this timesheet period 6 hours are being considered for overtime and since we are adding -4 to the Time Off in lieu we are actually banking 4 hours.
Please refer the attached screen shots for better understanding.

Daily Overtime Rule:

User B TimeSheet:

Modified TimeSheet:

Final TimeSheet: