Using measure on Pie Chart Value, it cannot filter the table

Hi, 

Hoping the experts can help me with the pie chart issue below.

In the dashboard, the score weighting and scale are set by parameters. 

Score = height * height parameter value + weight * weight parameter value
, which (height parameter value + weight parameter value) = 1

Grade scale = if Score > A grade parameter value, A
                       if Score <= A grade parameter value and >C grade parameter value, B,
                       C

Now, I created a pie chart by 3 measure by counting A, B, C grade separately , since I cannot add the grade measure to the pie chart value.

However, this pie chart is not able to filter the table. 

How to make relationship between the pie chart and table in this case? I expect when I select "A" in the pie, the table show only "A" result.

Thank you for your time.