Get values from multi select field using search.lookupFields

How do you retrieve values from a multi select list using Suitescript 2.0? I am trying to look up the subsidiaries of an item record and the look up result length is only one, when there are multiple subsidiaries associated with it.
item_subsidiary = search.lookupFields({
                                            type: 'item',
                                            id: item_InternalId,
                                            columns: ['subsidiary']
                                        });
                                        log.debug('Debug', 'item_subsidiary.length : '+item_subsidiary.subsidiary.length);

item_subsidiary.subsidiary.length returns '1', even when I have two subsidiaries on the item.

Also, how do i get both values?