Global
parameters enable you to specify a variable whose value can be changed globally at any time.
You can use global parameters in filters, calculated items, and
aggregated measures.
If your selected
visualization contains a
data item or filter that uses a global
parameter, then the parameter appears on the
Parameters tab.
The same value for the parameter is used globally in your exploration
for all filters, calculated items, and aggregations that include the
parameter.
Note: Global parameters are shown
on the Parameters tab only if a data item
or filter that uses the global parameter is used in the selected visualization.