Using Parameters
For example, a dashboard user can use a list to select a value. That value sets a parameter that in turn sets a filter, calculation, or URL action to the chosen value. Then the visuals in the dashboard change based on the choices of the user.
To make the parameters accessible to the dashboard viewer, you can add a parameter control. A control can appear as a list of options, a slider, or a text entry area. You can also set up cascading controls, so that a selection in one control filters the options that display in another control. If you do not create a control, you can still pass a value to your parameter in the dashboard URL.
Parameters must be connected to an element in your analysis, regardless of whether they have a related control. You can reference parameters in calculated fields, filters, dashboard and analysis URLs, custom actions, and titles and descriptions throughout an analysis.
For example, if you use a calculation with a parameter, you can transform the data that is shown in an analysis. If you add a control with a filter to an analysis you are publishing, the dashboard users can filter the data without creating their own filters. Using controls and custom actions, you can let dashboard users set values for the URL actions.