Go to : Content/PortalTeleport/Blueprints/Maps/BaseStreamingLevel

# What is Base Streaming Level?

This level is a basic empty level where you can place the main systems and even use the singleton principle. You can make fast and efficient transitions between levels by adding sub-levels within this level.

Go to : Window/Levels

# Add Sub Levels

 Create a basic level
 Design and save created level
 Open BaseStreamingLevel
 Open Windows/Levels window in the editor 
 Drag your level under Persisten Level