There's always the option to apply for a higher level position outside the graduate program if that's what the graduate wants. Once the graduate program is over there's also the chance to apply to a higher ranked position. However, if a graduate does not apply to higher level positions then there's a risk they get stuck in a low level rank, so it's up to the graduate to have initiative and confidence to go for higher roles.
I am currently in a graduate rotation program, however still on my first rotation. However, I am hopeful that the graduate program provides me with lots of exposure and I get the opportunity to both figure out what I love in the engineering space, and will have the opportunity to progress in my career in the role I was most interested in.