How to give access to a custom dashboard and data within it

Summary:

How to give access to a custom dashboard and data within it

Content (required):

Hi,

We have some custom dashbaords developed and each dashboard has multiple analysis within it. At the same time, we also have custom roles created and assigned to users. We observed that some users with role A are able to access the dashboard and other users with role B are NOT able to access the same dashboard.

Can someone please help us understand how to give access to a dashboard for role A or role B? do we need to add any roles or privileges within the custom role? if yes, how to find those roles or privileges?