Stop WordPress Users from Seeing Posts From Other Authors
In some situations, you may want authors to log in to the WordPress admin area and only see their posts.
It's as simple as installing PublishPress Permissions. By default, this plugin will hide all the Posts from other users. When users in the “Author” role go to “Posts” screen they will now only see their posts.
To configure this option, go to Permissions > Settings and then click the “Core” tab. There is setting called “Hide non-editable posts”.
What this means is that users won't be able to see any posts that they can't edit.
Users in the “Author” role can only edit their own posts, so they will only see their own posts.