I assume that your Year is appearing in your Measures List. Tableau likely did this since upon connecting to your data it saw your year as a field which was nothing but numerical entries and therefore guessed it was a measure. I'd bet that if you were to drag and drop your InvoiceYear field from the Measures List to the Dimensions List and then were to use the resulting dimension on the filter shelf, you would see your problem fixed.
Hope this helps,
Hi Dan. I thought about that and tried it both as a dimension (where I started) AND as a measure. Same result. I even checked the values thinking that perhaps the date was creating bad values but the domain seems correct.
And strangely enough, when I use the Invoice Head FiscalYear field it gives me the same option. (The FiscalYear field you see in the Filter is the GL_Budget table's field.)
Since it looks like the field is coming from the secondary data source in this sheet, have you tried switching the relationships here so that the Combined Financials LIVE data connection is the primary? If you can use it as a filter as you desire with the data connection as the primary, it may just be a limitation of blending in as it stands currently in version 7.
If this still doesn't fix it, try the following:
1) Create a new calculated field using the same formula
2) Immediately move the resulting field from the Measures to Dimensions list
3) Then try and add this to the filter shelf