I have a requirement, there is report with graph and legend , for example - In legends i have A,B,C,D, i have bar graph A+B+C+D on top of each for Q1, Q2 , Q3, Q4. So here when i click on the legend A it should show only A on the graph for all quarters not b,c,d, same when i click on B,C and D. so when i click on legend it should show only that in the graph. Master detail linking does not work for this as i tried it.
I don't think legends can be interactive (do let me know , if u can achieve this) .
However , If you can set the dimesion column (whose members are A,B,C,D ) as a dashboard prompt and make it prompted in the report . I'm sure you already thought of that though !