If you want to start a batch file from an other batch file you can use the start command.
If you want to hide the command line window, that will be displayed by default, use the /B parameter.
start /B /wait Test2.bat
When you execute Test1.bat on the command line, the Test2.bat will be executed without showing a window.
(The Test1.bat will wait until Test2.bat is finished, because the /wait argument is supplied.)