I'll assume that you CAT dimension is named Category.
Here's what you do:
Use a line chart (presentation > use zone)
keep your time dimension
Add another dimension: Category
as a measure: Only have 1 measure: Sum(Cost)
When you filter with a CAT you'll only have the stacked CATs.
Per analogy in the example below:
Dimension 1: Year
Dimension 2 : Region