The Report By Control is located at the top left of the Report Screen. It is unique among the controls as its icon changes depending on the dimension that is selected.
What the control looks like
What is a dimension?
A 'dimension' in Ipiphany is the method of classification that you are choosing to group records by. For example, if you choose a dimension of 'Country' then Ipiphany will return records grouped by the names of countries.
Selecting a dimension
Click on the Report By control
Choose from the list
Select the specific option if required
The Report By control will close and your selection will be applied