To delete a duplicate
data item, an aggregated measure, a calculated data item, or a derived
data item, right-click on the data item in the Data pane,
and then select Delete.
Note: If the deleted data item
is used by a visualization, then a confirmation message appears. The
deleted item is removed from the visualization.
Note: You cannot delete a data
item that is included in a hierarchy. You must remove the data item
from any hierarchies before you can delete it.