How to use a filtered computed property with ember-drag-drop sortable-objects?

I'm using ember-drag-drop to implement a sortable list. This worked fine until I needed to implement a text filter on the list.

The filteredItems is a computed property which filters the original list based on a user's text input.

filteredRules: computed('items', 'term', function() {
  let term = this.get('term');
  let items = this.get('items');

  if (term.length > 0) {
    return items.filter(item => item.conditions.some(cond => cond.field.toLowerCase().indexOf(term) > -1 || (cond.term && cond.term.toLowerCase().indexOf(term) > -1)));
  } else {
    return items;
  }
}),

The problem is that a computed can't (normally) be written back to.

How can I still allow sorting of the original items data set while still allowing filtering?