How to create a data column that changes with dropdown box menu

I downloaded the template and, after unprotecting the Financial Report sheet, could see that SelectedYear drop-down was a list sourced from the lstYears range.  lstYears is a convoluted dynamic range (i.e. it uses the OFFSET function to define itself) which boils down to C5:I5 on the Financial Data Input sheet.  Why they didn't just define the range name directly is beyond me!

If you change the headings in lstYears to month names the SelectedYear drop-down will let you choose from the month names.

You may want to change the range names to lstMonths and SelectedMonth to eliminate confusion.