Vector plans can store layer information, including outlines, text, walls, room names, and other drawing details. You can access the various layers, and chose the ones you wish you view inside the Viewport pane by clicking the arrow beside the plan name.
Fig1. Plans pane
Beside each layer is an eye and by clicking on the eye it will turn the layer off/on.
Fig2. Plan layers
A quick way to hide or show all layers of a vector plan is to right-click on the white space in the Viewport and select "Hide all Layers" or "Show all Layers"
Fig3. Hide / Show all Layers