Filter Measure with its Aggregated Value by Year

Hi,

I don't think that will be possible.  The only way to create a slicr for key customer is to create a seperate table or in the data table itself, have a sperate column identifying the Type of Customer.  Even if you can create that spare column in your data table, the problem would be that a slicer selection will not recopute that spare column.  Calculated column formulas only update when the model is refreshed (not when a slicer selection is made).