You just need to specify the fully-qualified classname, i.e. packagename.ClassName. So, if I understand your project structure correctly, your controller class is scaterChartController1 and it is in a package called testPac.view1,2. So your fx:controller attribute should have the value fx:controller = "testPac.view.scaterChartController".
In SceneBuilder you can set this in the "Controller" pane which is in the bottom left of the screen (expand it if necessary):

Footnotes:
- You should follow proper naming conventions, so all class names should begin with an upper case letter. scaterChartControlleris not a proper class name according to the standard convention. Similarly, package names should be all lower case, so "a package calledtestPac" also violates the convention.
- The package name is evident from the first line of code. I am assuming you have a package name of - view, so the first line of code in the controller class will be
 - package testPac.view ;
 - Modify the - fx:controllerattribute accordingly if the package is different to that.