I don't think it is necessary to hide your bachelor's degree. If you performed excellently in your bachelor's degree, then it is a good sign. It tells the visa officer you are a serious student. Most people change their degree courses from time to time and so the most important thing is to come up with a valid and genuine reason for going for a second bachelor's degree.
Going for a second bachelor's degree doesn't mean your visa will be automatically rejected. There is some likelihood that it might be rejected but I know a lot of students here in Germany who had their visas approved and are currently studying for their second bachelor's degrees. The most important thing is to portray to the visa officer that you are a serious and genuine student whose sole purpose is to study. However, if you did poorly in your first bachelor's program, then it can be a huge red flag.