It would appear that your drive has been partitioned at least twice.
In the first instance the partitions appear to have been 524GB + 252GB + 224GB.
The second (and most recent?) partitions appear to be 331GB + 349GB + 321GB.
The drive now has a single 1TB partition (Primary A).
I would double-click each of the partitions in the second set and expand the Root. Confirm that you can now see your correct file/folder tree. You could do the same for the first set (to confirm that they are old data).
At this point you should consider backing up your data to a second HDD.
Otherwise, r-click the Primary (A) partition and select Remove the Partition.
Now r-click the 331GB partition and select Insert the Partition (Undelete).