I have a Custom Object X that has Org Wide Defaults of "Private". The owners on the records are always internal users.
We would like to share the object with customers that belong to the account for which the record is related to.
ObjectX 1 is related to Account 1
ObjectX 2 is related to Account 2
User 1 belongs to Account 1.
User 2 belongs to Account 2.
User 3 belongs to Account 1.
All three users are customer community users.
User 1 and User 3 should be able to see all the Object X records for Account 1. User 2 should be able to see all the Object X records for Account 2.
User 2 should NOT be able to see all the Object X records for Account 1.
I have read that this is possible using Sharing Sets, but we do not have this feature in our org. I know we could accomplish this with Apex Sharing, but I would like to use that as a last resort.