N/ui/serverWidget Module
FieldGroup.isCollapsible
Property Description: Indicates whether the field group can be collapsed. The default value is false, which means the field group displays as a static group that cannot be opened or closed. If set to true, the field group can be collapsed. Only supported for fields on serverWidget.Assistant objects
Type: boolean
Supported Script Types: SuiteScript 2.0 Suitelet Script Type and SuiteScript 2.0 User Event Script Type (beforeLoad(scriptContext))
Module: N/ui/serverWidget Module
Since: 2015.2
Search NetSuite - https://system.netsuite.com/app/help/helpcenter.nl?search=FieldGroup.isCollapsible

// Code Example 1

//Add additional code

//...

var form = serverWidget.createForm({

    title : 'Simple Form'

});

var fieldgroup = form.addFieldGroup({

    id : 'fieldgroupid',

    label : 'Field Group'

});

var field = form.addField({

    id : 'custpage_textfield',

    type : serverWidget.FieldType.TEXT,

    label : 'Text',

    container : 'fieldgroupid'

});

fieldgroup.isCollapsible = true;

//...

//Add additional code



//SOURCE: https://system.netsuite.com/app/help/helpcenter.nl?fid=section_4335348134.html