Hey Phil,
Currently, there isn’t a simple way to sort by Reference field, but you can code a workaround by adding field value from referenced collection into separate column that will be filterable. Your code might look something like this:
import wixData from 'wix-data'
export function CollectionWithReference_beforeUpdate(item, context) {
// Get id regardless of whether you're adding the item through site or Content Manager
const referencedItemId = item.referenceField._id || item.referenceField
// Get data from referenced collection
return wixData.get('RefCollection', referencedItemId)
.then(ref => {
// Add value that you'll use to filter your collection
item.filterableField = ref.fieldToUseForFilter
return item
})
}
And lastly, you can easily sort Dataset by field Last Updated.
Hope that helps!