def _create_filter(self):
        """Create a filter of all of the dependency products that we have selected."""

        self._product_filter = {}

        for chip in itertools.chain(iter(self._family.targets(self._tile.short_name)),
                                    iter([self._family.platform_independent_target()])):
            for key, prods in chip.property('depends', {}).items():
                name, _, _ = key.partition(',')

                for prod in prods:
                    if prod not in self._product_filter:
                        self._product_filter[prod] = set()

                    self._product_filter[prod].add(name)
Create a filter of all of the dependency products that we have selected.