I am sorry for lacking the module "Search Top" in our documentation.
Here is my instructions to create this module.
Step 1: Log in the administration.
Step 2: Go to Extensions/Modules Manager/Add New
You need to create the module "Search-Top".
+ Module type: Search
+ Position: search-top-level
+ In the tab "menu assignment": You need to assign for the menu which you want to use this module.
You can see the attached images to get more configurations.
Step 3: You need to pay attention to the layout.
For example, you select the layout "tz_exception_joomla - Home 1"/.
In the tab "layout", you go down to find the third block "Header". You will see the row "search-top".
You can see the configuration in the attached images.
Step 4: You go to your site and refresh and check whether the module appear or not.