Yes you are right. There is an option to filter your choice. However, what happens when you choice for two let's say in our case "Manufacturer" and "Dropshipper", it returns values including only either of them and then you have to reach there info page in order to find out whether a particular supplier meets both conditions or not.
Moreover, I requested for free dropshipper. I need to check whether these suppliers meet this third condition or not after visiting each of them one by one.