How to update a Multi Select custom field using ScriptRunner Behaviour?

[brbojorque]

Can anyone help how to basically update the multi select using ScriptRunner in the behaviour.

This is the error I'm getting:

[SR Behaviours] Adding listeners ...: data {customfield_10152: {…}, __I18N__: {…}} firstRun false
batch.js?agile_global_admin_condition=true&baseurl-check-resources=true&healthcheck-resources=true&is-server-instance=true&is-system-admin=true&jag=true&jaguser=true&locale=en-US&nps-acknowledged=true&nps-not-opted-out=true&richediton=true&spectrum=true:3853 [SR Behaviours] Unrecognised backend ID, or possibly field with no available options: customfield_10152
batch.js?agile_global_admin_condition=true&baseurl-check-resources=true&healthcheck-resources=true&is-server-instance=true&is-system-admin=true&jag=true&jaguser=true&locale=en-US&nps-acknowledged=true&nps-not-opted-out=true&richediton=true&spectrum=true:3853 [SR Behaviours] Field not found: customfield_10152

Here's my code so far but it is not working:

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

@BaseScript FieldBehaviours fieldBehaviours

def fieldName = "Multi Select Field"
def field = getFieldByName(fieldName)
def optionsManager = ComponentAccessor.getOptionsManager()

def customField = ComponentAccessor.getCustomFieldManager().getCustomFieldObjectsByName(fieldName)[0]
def formMultiSelect = getFieldByName(fieldName)

log.debug(formMultiSelect)
def config = ComponentAccessor.fieldConfigSchemeManager.getRelevantConfig(getIssueContext(), customField)

def options = optionsManager.getOptions(config)
formMultiSelect.setFieldOptions(options)

def parentOption = options.find {it.value == "A"}
formMultiSelect.setFieldOptions(options)
formMultiSelect.setFormValue([parentOption.optionId, -1, -1]) //This code does not work