% of Employees on Talent Review meeting w.r.t Succession Plan

Summary: I am looking to calculate the % of employees on a Talent Review box those who are on Succession Plan. SO for example on the 9-Box matrix box- Future Star we have 5 employees across 2 talent reviews and 3 of the employees are on Succession Plans, then I am looking for showing a graph which will show Future Star on Succession Plan as 60% approx.

Issues I am getting;

1) I have to filter the succession plan name, it doesn't take automatically from talent Review meeting even though it is added on the Talent Review. I have filtered it on the selection steps.

2) When I select Total count employees on TR and Count of Candidates, the count of candidates is not coming up correctly based on talent review