First of all, did you know that Tableau handles your fiscal year for you? Right click on your date field and under Default Properties you can tell tableau when your fiscal year starts:
Having said that, let me recommend that you don't use a filter. Use a parameter, and then make a calc to figure out what you should show your user based on the month selected.
Give me a bit, and I'll hack up something.
EDIT: My bad. You already have a parameter. I'll do something with that.
thanks for the help, Joe.
Looking forward to seeing your solution
THanks so much for the proposed solution. I understand a good majority of the code; however, I noticed you are using the today() function. In my actual dataset I have multiple years (goes back to 2012). I think I need to change the Today part if I wanted to set my parameter to lets say "Dec 2013" -> I would then expect the outcome to show Oct, Nov, and Dec 2013.
I hope I'm being clear.
Thanks for your continued help!
My filter in the example was simplified. I was just doing current year. You might want to give the user another filter to select the FY to view. (And then you could probably just do away with the FY Today calc.)
Here's another solution:
[Month Year]<=[Select Date] AND [Month Year]>=DATEADD('month',9,DATETRUNC('year',DATEADD('month',-9,[Select Date])))