FieldPluginBase: How to test based on views field raw value?
For the untranslated field value get first the untranslated entity:

if ($entity = $this-&gt;getEntity($values)) {
  $untranslated_entity = $entity-&gt;getUntranslated();
  $untranslated_value = $untranslated_entity-&gt;field_example-&gt;value;
}