Answer

Step 1: Create a Parameter

1. Click the down arrow next to Dimensions in the data pane and select Create Parameter…
2. In the Create Parameter dialog, do the following and click OK:
   1. Name the parameter [Activate the category filter?]
   2. For Data Type, choose Integer.
   3. For Allowable values, select List
   4. Add two options to the list:  0 for "Deactivate" and "1"  for activate
3. Right-click [Activate the category filter?] in the data pane and select Show Parameter Control.

Step 2: Create the following Calculated fields

• Select Analysis > Create Calculated Field...

    CASE [Activate the category filter ?]
    WHEN 0 THEN NULL
    WHEN 1 THEN [Category]
    END

Step 3: Enable the Activate Filter calculated field

• Drag [Category Filter Controller] to the Filters shelf.
• In the Filter dialog, check an option being displayed and click OK.