Iterate and collaborate with other developers using the Developers folder.

The folder for Developers in the “ Content Browser ” is a place to copy assets and work on them without worrying about breaking your project. Use the Developers folder to experiment, from small asset changes to project-wide refactoring.

When you share a project with other developers, each developer has a separate folder.

The Developers folder uses your Windows username, with characters not allowed in Unreal Engine folder names, such as periods or spaces, removed.

Enabling the Developers Folder #

If the Developers folder is not visible in the Content Browser, enable it as follows:

1. in the “ Content Browser ”, click “ Settings ” .
2. From Settings, enable Show Developers Content .

Collaborating with Other Developers #

If you use source control, configure Unreal Engine to show assets in other developers' folders as follows:

1. in the “ Content Browser ”, click the “ Filters ” .
2. From the Filters menu, select Other Filters > Other Developers .

Excluding the Developers Folder from Cooked Builds #

To prevent broken or unfinished assets from being packaged accidentally, exclude the Developers folder from cooked builds as follows:

1. From the main menu, open Edit > Project Settings and find the array of directories to Never Cook.
2. Click the Add (+) button to add an element to the array.
3. Click … to open the project's folder list.
4. Click the folder named Developers to select it.

Source:

https://docs.unrealengine.com/5.1/en-US/developers-folder-in-unreal-engine/