Add a filter function to the translate interaction. This filter is similar to the one present in the select interaction options and provides the ability to dynamically filter which features to include in the translate interaction. Adding the existing "features" options allows further filtering to take place. In this case the filter is first applied, and features that are passing the filtering need to be present in the "features" options to be further kept. The default filter function always return true (no filtering).
André Garneau