A dual drive has a partition which is a SSD and a partition that iis HDD. While trying to defragment the HDD partiion you will be told it is a SDD and not to be defragmented. Some software should allow you to get pass a warning, Defraggler that is, but I tried and found no such ooption. I guess it has been removed with an update.
How many drive letters do you see? If you see just one, then the whole SSD/HDD game is hidden, and the OS does not know whether part of the file is on flash or on platter. The drive' firmware makes the decision what and when to move between flash and platters.
If such a software really exists, it should be provided by the drive' manufacturer.
But - why you think you need to defrag your drive? I haven't defragged my drives since XP days...