Calc values in forecast scenario by referencing S#Actual, V#Trailing12MonthAvg
I have a forecast scenario S#AugFcst_7_5 with the following properties:
WF Time = 2023M7
WF start time = 2023M1
WF end time = 2024M12
# no input periods = 7
I have a Finance business rule function that is being initiated using a dashboard button in the workflow. The dashboard button calls DM Sequence/step where data units are defined as WFScenario and T#root.WFTimePeriods, business rule = FPA, function name = ttmaverage
In the function (ttmaverage) I am limiting the calculation to only the base periods of 2024 and I want it to calculate V#Periodic by looking at S#Actual, V#Trailing12MonthAvg, T#2023M6
I receive the following error when executing it:

I believe the error is because I want it to calculate off S#Actual, T#2023M6, V#Trailing12MonthAvg and that includes time periods that fall outside the range of my WF scenario AugFcst_7_5.
I tested this by changing the formula to look at S#Actual, T#2023M6, V#Trailing6MonthAvg and the calculation works but obviously does not give me what I need. If I use V#Trailing7MonthAvg or greater then it fails.
How can I calculate periodic values for S#AugFcst_7_5, 2024 base time periods from S#Actual, T#2023M6, V#Trailing12MonthAvg but still have my S#AugFcst_7_5 WF start time as 2023M1?
