Hi @ringgo
You can create a calculated field that combines ‘month’ and ‘year’ strings and produce a ‘Date’ value; For example, consider ‘month’ and ‘year’ fields having the following values:
month year
JAN 2020
FEB 2020
MAR 2020
you can create a calculated field with the following expression that will produce a date value:
parseDate(concat({month},‘-’,{year}),‘MMM-yyyy’)
You can then use this new calculated field to filter for last ‘N’ months.