The additional recipe ranks can be obtained either by exploring the outdoor Broken Isles zones or as rewards when you dive into the dungeons of the region. If you’re feeling up to the challenge, you can aim to hit skill level 100 and player level 100 to open up profession world quests, which rewards higher rank recipes for your Legion gold making operation.
Edit 20 It’s been a week since this post and a lot of people are still reaching out to me with questions which is fine. I have had a few different people reach out to me to help make YouTube videos based off this guide and more info in BFA which I’m more than willing to do. Whoever gets the videos up first I will link them here for you guys to enjoy.