By default, WordPress users in the admin area can see all the Posts on the site. This happens regardless of whether or not users can edit those posts.
You can prevent this from happening by installing PublishPress Permissions Pro plugin.
After you install it, go to PublishPress Permissions > Settings > Editing and remove the “Lists other user's uneditable posts”
That's it. It will block users from seeing Posts that they can not edit.
When users go to “Posts” screen, they only see their posts.
The image below shows what a user can see on a WordPress site before PublishPress Permissions is installed and correctly configured.
And this next image shows what the same user sees after the plugin is activated and configured. Notice that the numbers across the top of the screen have changed. For example, “Published” has dropped from 20 to 8 and “Scheduled” has dropped from 28 to 20.
If you want to disable this option check out this guide to the list_post permission.