[Qlik Sense 3.0] Working Examples with selections:

var myApp = qlik.currApp();

var fieldName = "Year";
var field = myApp.field(fieldName);


field.selectAll();


myApp.field(fieldName).select([0], false, false);
myApp.field(fieldName).selectMatch('1997', true);
myApp.field(fieldName).select([0, 1, 2], true, true);

myApp.field(fieldName).selectAll();
myApp.field(fieldName).clear();

myApp.field('Territory code').selectValues([{qText: 'CHN'},{qText: 'USA'}], false, false);
myApp.field(fieldName).selectValues([1997, 1998, 1999, 2000], true, true);