Parameters are right now single value. You can only pick one value out of a predefined list.
What would be great is to make Parameters accept multiple values!
String Parameter for Region. I have 4 values: East, West, Central, South.
I make the Parameter multi-value (new option).
When used the parameter control allows me to choose more than one values (as many as I want) like Quick Filters work.
Automatically and by default, the list of value presented also includes "all" which can be removed (like when you customize a quick filter).
Tableau would add a logical OR between each value.
If [Parameter] InList (string1, string2....., stringN) Then etc.
If [Parameter] = string1 OR [Parameter] = string2 etc.
East, West, Central, South, ALL, East+West, East+Central, East+South,....etc.
and code in calculated field using if then else what happens for each combination of values used. This is combersome and cannot be done if I have a lot of combination possible.
2- your quick filter returns a lot of values and the list is static - refreshing the quick filter each time is not good for performance for my dashboard and I would rather used a predefined list in my parameter.
Workarounds have been discussed and answered in the following community post: selecting multiple values in parameter. Multiple methods are discussed in the comments with further links. There is currently a survey for you to take to help the developers better understand the need and root cause of the problem here: http://community.tableau.com/ideas/1178 and specifically here: http://www.tableau.com/about/blog/2015/1/top-idea-request-for-feedback-dynamic-parameters.
I just wanted to say thank you for all the great ideas and thanks for being patient with us. I know this idea has been around for a while, but I want to let you know we're listening. It's a great idea, and it's important that you have the tools you need. If any of you are able to discuss this further, I'd love to hear more details about how multi-select parameters would be used? Do you imagine this being helpful outside of filtering across multiple data sources?
If ever have questions or concerns please don't hesitate to email me.
Although we've received a lot of feedback already through this thread, we want to verify that your priorities are properly captured. Your feedback will directly help shape the course of our planning. Thank you kindly for sharing your thoughts with us.