On the Architectural component tab you will find the Stretch Levels tool in the Add Level(s) section. 

This tool has two functionalities: one for stretching levels horizontally, and another one for moving levels vertically (with or without moving the levels above). You can toggle between the two functions of the tool from its quick properties after starting the tool: 

Stretch level horizontally

This tool can operate in both 2D and 3D drawing areas. 

To stretch a level horizontally, follow these steps:

1. Click the Stretch Levels tool, then hover the cursor to the side of the level that you want to stretch.
2. Click once on the side/edge that is highlighted.
   
   When using the tool in the 3D drawing area, use the Space bar to toggle to the Sides option in the quick properties before you click on the side.
   
   
   
   
3. You can either move the cursor to the desired distance or directly type the dimension in the quick properties. 
   
   
4. If needed, select the level and use the properties box to edit the level. Refer to the Editing a level section in this article.

Moving level vertically

This tool can operate in the 3D drawing area only. 

To move a level vertically, follow these steps:

1. Click on the Stretch tool then move the cursor into the 3D drawing area.
2. Use the Space key to toggle to the Floor/Ceiling option in the quick properties. 
3. Hover the cursor over the level that you want to move. Ensure the desired level is highlighted, then click. 
4. You can select either Floor that you added or the ceiling which will be automatically shows once you hover the cursor above the floor. (as shown below)
   
   
   
   
5. Move the cursor up or down to the desired elevation, or type an exact number directly in the Distance or Level elevation in the quick properties. 
   
   
6. The quick properties box has three values: Distance, Level Elevation and Move floor with ceiling/Move ceiling with floor. 
   
    or 
   
   • Distance: Difference from the current position. 
   • Level Elevation: Distance from base level (ground).
   • Move floor with ceiling/Move ceiling with floor: Move both floor and ceiling at once.