Combination of Year() and PeriodNext1() not working in a GetDataCell

I am trying to utilize a combination of Year() and PeriodNext1() within a GetDataCell, and it's not working. The combination of Year() and Period() within a GetDataCell works if you surround it with brackets, but once you add the Next1, it will not work. Any ideas as to how I can accomplish this?

Example of GetDataCell with Year() and Period() working fine: 

GetDataCell(BWDiff(V#MTD:T#|!Prompt_TimeMonth!|:S#|!Prompt_Scenario!|, V#MTD:T#[Year(|!Prompt_CurrentYear_Comp2!|)Period(|!Prompt_TimeMonth!|)]:S#|!Compare_Scenario2!|))

Example of GetDataCell with Year() and PeriodNext1() which gives an error:

GetDataCell(BWDiff(V#MTD:T#PeriodNext1(|!Prompt_TimeMonth!|):S#|!Prompt_Scenario_FW!|, V#MTD:T#[Year(|!Prompt_CurrentYear_Comp1!|)PeriodNext1(|!Prompt_TimeMonth!|)]:S#|!Compare_Scenario1_Bgt!|))

Error Message Received:

Thanks!