Hi. I am also an HR professional, having ventured in HR after working in hotel operations. You are right in surmising that companies are looking for people in mktg, finance, operations departments and so on. While I maynot have heaps of experience, I can put forth a few observations and questions that hopefully might help you. Here goes:
1. U r pursuing MBA from which institute? What is your motivation behind doing MBA? Is it getting a good job, creating a knowledge pool, want for education or other? Which semester ru studying in? Whatever may be the answers to these questions, you need to understand that a lot of education happens in an MBA course through own motivation. You will have to talk to ur seniors, peers, professors to get various perspectives. Reading books, participating in competitions (of Bschools) also will help in widening your spectrum. It is these things that will make you employable. It should be noted that in this time of quick returns, companies don't have time to train people, especially new talent in the company.
2. HR is and will be a support function for a company, which is typically seen as a cost centre with no direct profit contribution. Whereas, most other departments directly impact sales and hence money influx. Moreover, a company's HR dept is relatively smaller than any operational dept, and hence they naturally require less people in HR.
3. The MBA degree itself lacks credibility nowadays. Many industry experts feel, and even I agree, that there are so many MBA colleges and there is a general doubt on the employability of many MBA students.
4. What to do in this case is aligning urself with the industry. No matter which semester ur in, start doing internships with companies. It will serve 2 purposes- u will get to see HR function live, although from a grass route level; and u willl get to network. These are my- if flawed- opinions. Think about it.