Example: Please set up a standard user Samuel to view only records that are assigned to him. Sam should only view records that are under his name, he should not have access to view any other records.
Permission sets (all of them) should not have checked View all, Modify all options on Property object.
If any permission set has View all or Modify all checked, please do the following:
Following are the steps you need to take to set your users to view each other data:
5. Select sharing access type for the Object
6. Click Save.
Note: By using “Sharing Setting” everyone in the organization will be able to see each other data.
Step 2 (Optional)
Set specific user with Permission to see the data of other user when all Objects are set to private: