Leveraging operations work experience into MM/Boutique

I know of two people who went from BB OPS to BB IB. One networked his way in, the other did an MBA in between. Your best shot will be either networking or going OPS>boutique (not EB)>MM/BB. It will be tough moving from OPS to MM or BB simply because every time on of these jobs is posted, many applicants with IB apply. A bank would be hard pressed to pass over people with relevant experience for someone in OPS. I would start out by reaching out to contacts or simply cold emailing like you might have done in undergrad. Reach out to boutiques too. Good luck.