I need Guest users to my Community to be able to use the Global Search to search a subset of the Accounts in our instance. I have the OWD for Accounts set to Read. I can't think of how to restrict the OWD & still allow Guest users to see some of the Accounts. Is there a way to have a sharing setting for Guest users?
You would need to first set OWD to private, as you can't introduce restrictive sharing, only permissive sharing. Then, create a public group for your guest user, and create a sharing rule to share the accounts you want. Afterwards, you may need to create additional rules for authorized users, etc.