A public group is a grouping of users, roles, roles and subordinates, or other groups that can be used to share access to records or folders. A sharing rule is a rule that grants additional access to records based on certain criteria or ownership. In this case, the administrator should create a public group for the renewals team and create a criteria based sharing rule on opportunities that grants read-only access to the group for all closed won opportunities. This way, the renewals team can see all the opportunities that are eligible for renewal while keeping the account private. References: https://help.salesforce.com/s/articleView?id=sf.admin_sharing.
htm&type=5 https://help.salesforce.com/s/articleView?id=sf.sharing_rules.htm&type=5