If you are analyzing costs and not revenues, you need to tell the system that a positive variance is "bad" (and should be rendered in red 🔴), while a negative variance is "good" (and should be rendered in 🟢). The system will not values as "Costs" instead as as "Sales."
Depending on the structure of your dataset, you will be presented a list of possible variance calculations you can choose from, beyond the default aggregated difference. For instance, if you have a units column in your dataset, the system will be able to compute prices, and thus to split variance into its price and volume components.
It is also possible to calculate variance as an index, and as percent of revenues.
If you leave the "Choose dimension to plot on waterfall chart" widget on None the app will plot the total variance. If you select a dimension (such as Country, Product, Client,...) the app will plot variance along said dimension.
Alternatively, you can ask the app to calculate all the combinations along all the dimensions, and return a "variable dimension" variance calculation with the set of most relevant combinations. You can choose between 10 different possible sets of results. And you can drill down each result.