adding data access by role

Summary:

Added a data privilege to a security current custom role but need data access to go with that

Content (required):

we added a data privilege to a security role to enable reporting for our managers. Oracle support helped us with adding the data privilege but said that data access needs to be added to the users. we have hundreds of users assigned to the custom role. Is there a way to add the data privilege on the role level? or what is the most efficient way to accomplish this task?

Also, does anyone have a sql to extract the list of users for a given role? I cannot find a delivered report that can produce this list.