1. In Tableau Desktop, connect to the data source. For this example, connect to the Superstore data source.
2. In the Data Window, right-click the Order Date field, and then select Create Custom Date.
3. In the Create Custom Date dialogue box, do the following:
   • For Detail, select Years. Leave the Date Value selected.
   • If desired, give the custom date a name. In this example,keep default as  Order Date - Year.
   • Click OK.
4. Repeat steps 2 -3 to create custom dates for both month and day.

1. Select Dimension drop-down, and then select Create Parameter.
2. In the Create Parameter dialogue box, do the following:
   • Give the parameter a name. For this example, use Date Level Selector.
   • For Data Type, select String.
   • For Allowable values, select List.
   • For List of values, enter Year, Month, and Day, then click OK.
3. In the Data window, right-click Date Level Selector and choose Show Parameter Control.

Create a calculated field that displays the data based on the date level specified by the date level selector parameter.

1. Select Analysis > Create Calculated Field.
2. Name the field Date Selector, enter the following calculation, then click OK:
   CASE [Date Level Selector] 
WHEN 'Year' THEN [Order Date - Years] 
WHEN 'Month' THEN [Order Date - Months] 
WHEN 'Day' THEN [Order Date - Days] 
END

1. Drag Date Selector to Columns.
2. On the Columns shelf, right-click the Date Selector field, and then select Exact Date and Discrete.
3. Drag Sales to Rows.