How do I get the value of a Cascading selected list in a Script Runner Behavoir

[Marcela Junyent]

I need to check the the value of a Cascading selected list in a Script Runner Behavoir to set a date. 

I can't find the proper method:

def dueDateField3 = getFieldByName("Fecha Evento")
def riskLevel = getFieldByName("Cascading List Custom fieldd").getValue()

def dateToSet

if (riskLevel == "Acceso Liberado") {
dateToSet = new Date().plus(3)
} else if (riskLevel == "Seguridad Locativa") {
dateToSet = new Date() + 30
}else if (riskLevel != "1") {
dateToSet = new Date()+ 2
}

dueDateField3.setFormValue(dateToSet.format("dd/MMM/yy hh:mm a"))

How do I do it?