Dynamic Dimensions/Legends based on Slicer

So as far as I can tell there is no way to make a calculated column that "changes/updates" based on slicer selection.

Is there a way to get a similar experience with some hacks?

So the user is ment to pick a date range and for that date range it will calculate the "Days of Inventory Left", based on the sales in that period. I want to group the days of inventory left into clusters, e.g. 0-25 days, 25-50 days etc. 

If i do this on a calculated column, there will be no context of the slicer filter (the days they select), and it will calcualte for every day of sales. 

If i do the grouping in a measure with a switch or so, I can't use it as a legend on certain visuals where i need it to act like a dimension.

Is there a way to get the legend/dimension to be calculated dynamically? (Performance not an issue)