Formula to Get nth to Last in Comma Separated List

Question

I have a column with cells that contain months separated with commas. I need to return the nth from last month.

Example dataset:

Months	Nth from Last	Result
2024 May, 2023 October, 2023 May	2	2023 October
2023 October, 2023 August, 2023 May, 2023 January	3	2023 August
2024 March, 2024 February	2	2024 March

So based on the Months column I want to return the nth value (defined in the Nth from Last column) on the Result column. Note, this is looking from oldest to newest with the cells organized from newest to oldest. This will always be the case.

Answer 1

You may try:

=map(A2:A,lambda(Σ,if(Σ="",,choosecols(split(Σ,", ",),-offset(Σ,,1)))))

If you just want a single-cell formula, it would be:

=choosecols(split(A2,", ",),-B2)