Wow, that's interesting. So let me make sure I understand. She reached level 10 in Culinary as a chef, then switched to Painting. She got to level 9(?) in Painting. You got the Connections reward and had her take a job in Culinary, where she started at level 4. From there she was able to take the Mixology branch. I think a lot of people would be interested in learning about this. Thanks for checking it out!
In a little more detail, sorry for my poor English that you may misunderstand my story. She had worked as a Celebrity Chef and had completed the Master Chef Aspiration long time ago. After that, she changed her work to Painter Career. She started just level 1 at Painter Career. I wondered why and noticed that she didn't have Connections reward, so I purchased while working as a painter. When she reached to the top level(Master of the Real) of painter career, I decided to have a small test.
1. I let her quit the painter career and then let her get a job for painter career again straightaway, and she was allowed to start from level 9,Illustrious Illustrator .
I canceled this interaction because it was just a small test.
2. I let her get a job at Culinary again, then she could start from 'Assistant Dishwasher' without Connection Reward.
I purchased the Connection Reward again.
3. I let her get a job at Culinary again, then she could start from 'Mixologist' with Connection reward.
I followed the 3rd test. When she reached to the level 6, I got the pop up for choosing branches and I picked "Mixologist" Branch. Now she is going for the mixologist! I can let her husband sim goes back to Culinary career again, I'm planning to let him choose the Chef. His both cooking skills are completed so it will be very easy to get promoted.
If he starts from maybe level 6 or 7, then just let him stay in Business career LONGER, then maybe a couple of months later, he can try again, then he can be started from lower level at Culinary.
He had completed Mixologist branch while she was working at the Chef branch. This is what I found yesterday.