Fiscal Year as a dynamic filter

I know where the FY settings are for an Application and how to set it.  I also know how to use it on a Chart under the filter settings.  

But, I don't want to filter my chart by Fiscal Year.  Rather, I want my FY field to be a dynamic filter.  So, how do I create a field, and the formula, to put in FY based on another date field.  

Specific example, we have a Customer Sat Survey.  I can potentially use either date field.  Date Created or (user inputed) Date of Contact.  I want a FY field that looks at this specific date and assigns it to a Fiscal year and then puts that year in the field.  I can then designate that field as a dynamic filter.