Samsung has recently updated its Experience Launcher for the Galaxy S8, Galaxy S8+, and Galaxy Note8. The update will allow the handsets to rotate the home screen when the phones are held in landscape mode.
This feature was previously only found on the Galaxy S9 and Galaxy S9+. While it isn't a huge addition, there may be some out there that will be thankful that this update has landed on their devices. If you'd like to change the setting on your supported smartphone, you can head to the settings menu to do so.
First enter the Settings menu, then into the Display section and find the Home screen menu. If you can't find it, you can enter the Settings menu and search 'Home screen', this should show up in the search results. Once inside the Home screen menu, you can scroll down until you find 'Portrait mode only' and toggle it either on or off, depending on your preference. Those that want to be able to rotate the home screen can toggle it off.
You can use the image in the article for reference. Be sure that if you enable it, you have the auto rotate feature enabled in the drop-down settings menu.
Source: XDA Developers