Tableau’s native parameters have a couple of key limitations as of this writing in February 2018: The list of values is static and we can only select one value at a time, not a range of values. So when we want to do something like set up a viz with user-selectable top and bottom thresholds we have to set two parameters, not one, when what we really want is a nice range control like the view below:
What it looks like here is that I’m using a ranged “parameter” to change the mark color & shape whose set of possible values is based on other filters…which is what we’ve wanted in Tableau for awhile now. Now you might be asking “Why go to all this trouble, why not use Tableau’s JavaScript API or the (forthcoming) Extensions API?”. And my response to that is that not everyone has the expertise available to use Tableau’s APIs or D3 so we’ve got to make the best use of the tool that we have at hand. Curious about how can you build this for yourself? Read on to find out!