Honestly, if you had said anything after "Does working at MBB lead to xxx" I would have said yes!
So, yes, honestly, you can truly chart your own course at MBB. Moreso, the course you'd like to take is quite common from MBB (corporate executive).
In order to get to this position you desire, make sure to do the following while at MBB:
1) Create a strong name/brand for yourself and rise up the ranks
2) Become affiliated with Pharma + Consumer Goods
Target Pharma + CPG projects. Participate in the industry-specific events. Build up your knowledge base + resume to show that you really operate and understand this area
3) Network effectively (within and without)
Within MBB, make sure you know the right people (Principals, Partners) in these practices. They will ultimately connect you with your future job!
During projects, establish a strong reputation with the clients and stay connected with them afterwards. When the time is right, you'll be able to leverage those relationships to see if you can join their firms at a senior level.