LimitFoods.groovy

package examples

import com.atlassian.jira.component.ComponentAccessor
import com.onresolve.jira.groovy.user.FieldBehaviours
import groovy.transform.BaseScript

@BaseScript FieldBehaviours behaviours

def foodField = getFieldById(getFieldChanged())
def subFoodField = getFieldByName('Sub-Food')

def customFieldManager = ComponentAccessor.customFieldManager
def optionsManager = ComponentAccessor.optionsManager

def customField = customFieldManager.getCustomFieldObjectByName('Sub-Food')
def config = customField.getRelevantConfig(getIssueContext())
def options = optionsManager.getOptions(config)

def newFieldOptions = []

if (foodField.value == [null]) {
    subFoodField.setFormValue([]).setHidden(true)
} else {
    subFoodField.setHidden(false)
}

if ('Fruits' in foodField.value) {
    newFieldOptions.addAll(options.findAll { it.value in ['Apples', 'Bananas', 'Oranges'] })
}

if ('Vegetables' in foodField.value) {
    newFieldOptions.addAll(options.findAll { it.value in ['Spinach', 'Cabbage', 'Cauliflower'] })
}

subFoodField.setFieldOptions(newFieldOptions)