A multi-tier column chart can be used to compare different situations (actual, planned, anticipated, etc.) over a specified time period (months in a year, several years, etc.).
For this type of chart, the scenarios are mapped using metrics. So the user will need to define separate metrics (for the same set of category elements) representing each scenario. As an example, if you are looking at sales data across months and are interested in looking at how the actual and planned scenarios compare, you will have to define two metrics