Navigational Tiers are used to move through the various levels of a project and these are located above the Floor Map pane.
When the Fleet Designer creates a new project, the application creates Navigational Tiers for a country, site, building, and floor by default. Use the Navigational Tiers to add locations and create a structure for each project that requires asset plotting.
For more information about creating a project structure, refer to Creating Project Structures.