The tile filter is a child definition to a detail screen field with an edit type of list tile view. A tile filter defines the property within the object type being listed upon which the items listed in the parent field can be filtered. This includes both manual, user defined filters as well as barcode scan filters.
A tile filter targets an object property within the object type being listed by the parent list tile view field. For this property, the tile filter then defines whether or not the user can filter on this property manually, and whether or not scan filtering is enabled for this value within the list tile view.