How much cleavage to show is a personal decision, but at work too much can definitely get in the way of your ambitions.
If you are going to work to build a career, then you need to be noticed for your work, your achievements, your leadership and your vision.
You need a style that reinforces those values.
If your work style speaks more strongly about your sex appeal, that is what will be noticed and remembered. You might gain popularity – but be less likely to be taken seriously or considered for promotion.
Cynics might say that being noticed for your bosom can get you promoted, and that may be true once or twice – but it won’t build you a lasting career.
Many women with larger breasts choose work bras to flatten and minimise, preferring high necklines – then change to push-ups and plunges after dark.
Displaying cleavage at work will get noticed, but it might mask your actual job abilities and stand in the way of serious promotion.