import java.util.List;
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;

public <O> List<O> getObjectWithAttributeEqualTo(Map<?, O> MyMap_Arg, Function<O, ?> MY_AttributeValueExtractor_Arg, Object MY_AttributeValueToEqual_Arg) {
    return  MyMap_Arg.values().stream().filter(o -> MY_AttributeValueExtractor_Arg.apply(o).equals(MY_AttributeValueToEqual_Arg)).collect(Collectors.toList());
}

HashMap<Integer, Car> myHashMap ;

List<Car> redCars = getValuesWithAttributeEqualTo(myHashMap, Car::getColor, "red");

List<Car> redCars = getValuesWithAttributeEqualTo(myHashMap, car -> car.getColor(), "red");