Dual degree obviously saves time and money. You are able to complete both your Bachelors and Masters. But it is obviously more preferable to acquire any degree one by one. If you really want to get into certain specific industries under business and management you should go for BMS. As the course is revised every five years so you get to learn many new things about the industry. You can even study further after BMS  for securing a good job in the future.

Dual degree is good if you are determined and planning to to get your masters in the specific subject. If you are ready to commit to that then even Dual degree is a good choice for you.

Good luck .