Hey,
So I don't know about this degree specifically, but generally to have your units from your old degree credited to a new one when you transfer, your new degree needs to have units that are equivalent to the ones you've completed. Because of this, it's unlikely that you'd be able to get units from applied science counted towards a bachelor of design (meaning you'd have to start from year 1), however it's more likely that you'd be able to get them counted to a bachelor of science (so you wouldn't have to start from year 1, but wouldn't necessarily go into year 2 either).
It would be a good idea to check with Melb to see what courses from the RMIT degree they would accept for credit transfer.
If they'll accept credit for all of the courses you do in first year at rmit, then it'll be like going straight into second year, however if they'll only accept some, your degree will take slightly longer as you'll do more units in total across both unis than needed for one degree.
EDIT: Also worth noting that uni isn't split into years like high school is. For the vast majority of degrees, you won't have set courses to do each year and people within the same degree may choose to do the same courses in different years etc. I.e. being in the second year of your degree won't mean that everyone else in your classes is also in their second year.