Find Best Fit in succession planning

Summary

How does find best fit work in succession planning?

Content

We have been looking at Succession Planning. I see there is a button for Find Best Fit, but it is grayed out. I thought that if I highlighted on of the employees in the list that it would work like the talent pool button does. I'm not sure if this is a security issue or if there is something we don't have set up in our environment. Does anyone have any experience with this? Looking for any suggestions. Thanks.