Follow the following steps to make a menu/sub-menu

You should have made an article before starting this tutorial

Choose ... Menu > Main Menu

 and click on "New"

 Give a name, say "Transistor"

 Click on "Select" for "Menu Item Type"

 Click on "Articles" to expand it and choose "Single Article"

  Click on "Select" for "Select Article"

 Select the article named "Transistor"

 if you save it at this time the menu will appear as a main menu item. To make it as a sub-menu you need to click on "Parent Item"

 Choose appropriate menu

 Now click on "Save and Close"

 You are done. Let is check it. Refresh the page and check that you menu is under Technology > SketchUp  shown as "Transistor". Click on it as you will see corresponding page.

 That is the end of this tutorial.