The waterfall chart is one of the most powerful standard visuals in Power BI given its ability to compute and format the variances of individual items between two periods by default. The items representing the largest variances are displayed as columns of varying length, sorted and formatted with either an increase (green) or decrease (red) color. This built-in logic and conditional formatting makes waterfall charts both easy to create and intuitive for users.

In the following example, the Internet Sales of the last two completed months is broken down by Sales Territory Country: 

The Internet Net Sales measure is applied to the y axis input field, and the Calendar Yr-Mo and Sales Territory Country columns are applied to the Category and Breakdown input fields, respectively. For this visual, the Max breakdowns property available under the Breakdown formatting card is set to 4 and thus only four countries are displayed. The other breakdown item, formatted in yellow by default, is used to summarize the variances for all items not displayed as a breakdown column. In the preceding example, the relatively smaller variances from Australia and Germany are automatically rolled into the other item.

As per the following image, a filter is applied to the Calendar Month Status column to only include the Prior Calendar Month and the 2 Mo Prior Calendar Month values: 

This filter results in only two month values being available to the visual and ensures that the visual will update over time. For example, in March of 2018, the visual will automatically update to compare January of 2018 versus February of 2018. This filter can be applied at the report level, page level, or visual level scope, depending on the scenario.