I love the filled maps in 7, but 5-digit ZIP codes are usually too granular for my data. I like to look at things by 3-digit ZIP codes. I can create the 3-digit ZIP (3ZIP) easily enough by doing a (LEFT, ZIP, 3) on the variable.
But I would like them to become their own shapes, so that I could color the 3ZIP by a variable in my set: Number of students enrolled, or average financial aid awarded. I could easily create groups but often my data sets won't have every ZIP code in them, so manually grouping might overlook ZIPS that would occur in future sets, and even then, I'm not sure I can get Tableau to create it as one new, large filled shape.
I suspect this is some sort of grouping using SQL, where you group by the distinctive (LEFT, 3) variable, into 098, 348, 606, etc. But I'm at a loss about how to do that and then allow the shapes to be colored by other variables in the data set.