Dear Madhuri,
You have worked as a HR Executive and now you have been designated as BDE. Designations hardly matter, what matters is the work and authority. If you feel the work allotted to you is interesting and challenging and moreover, you are confident to handle it, well there is no reason to deny the new assignment. On the other hand, I always suggest that people of one branch should not restrict their knowledge and understanding to a particular area, but it should be many -fold. HR people must know production, marketing, accounts, business etc and vice-versa.
You may have any field, but hard work, study, good knowledge, sincerity, understanding, fairness and such things are indispensable.
I suggest you can accept new assignment and prove your are a good executive by accepting challenges.
Good luck.
Adv. K. H. Kulkarni