An option would be to use a CROSSTABLE LOAD prefix to transform your data:
CROSSTABLE (Cs, Value)
LOAD * INLINE [
dimension,c1, c2,c3, c4
dim, 1,2, 5, 8
dim, 1,3, 5, 9
dim, 0,2, 6, 8
Then create a chart with dimensions dimension and Cs and a single expression
Then limit your second dimension to show only top 2 expression values.
You mean, using multiple dimension values?
So you want to show top 2 Cs per dimension value, then sort the complete chart descending?
I don't think you can get this with two dimensions, but maybe with a single calculated dimension and an expression that filters the Top2.
=dimension & ' - ' & Cs