Item Plan gives users the ability to plan at any level within the hierarchy and have the changes spread up or down.
Let's say we want to make bottom up (Style Level) adjustments and see the impact of these changes on the Department Level totals.
You can achieve this by grouping by Department and Style and select show totals next to Style. This will make the Department selection collapsible, so that you can either plan at the Department Level or make changes on the Style level and have them roll up.
Note that you can do Choice Level or Size Level adjustments as well if you choose to do so.
Below is a quick video that puts it all together.