Or if you have a Date field in your data you can use that to create a new Year-Month field which you can use as your dimension. To do this you can use this in your script:
date(monthstart(DATEFIELD), 'YYYY-MMM') AS YearMonth,
That is how I would do it
If you have a month and year field you can also solve it with a calculated dimension.
The expersion is in the attached example.
Thanks but i want to get growth by previous year like
2012-12 / 2011-12
(2824 / 2531) -1 = 12%
2012-11 / 2011-11
(3147 / 3048) -1 = 3%
like ways for other months upto rolling 24 months.
And i have month year field also in different table but dont know how to calculate the growth of current month vs previous year month upto rolling 24 months.