Prevent a user from viewing ALL succession plans

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Hi experts,

we are working with custom job roles and creating data roles based on various types of visibilities to be assigned to all users. In particular, our HRBPs should have visibility only on their respective succession plans (the ones of their areas of responsibility/the ones they are owner or viewers) but they are currently able to view all the succession plans, even the ones they have not been added as administrator/candidate manager/viewer.

Can anyone tell how to revert this situation and to make them view only SP based on their cones of visibility?