And it sounds like you have a failed truss. The top and bottom "studs" are called the top chord and bottom chord. From your description, the diagional bracing has buckeled. I personally have never seen residential trusses that used all metal bracing between the upper and lower chords. They are usually 2x4 bracing held to the chords with nail plates.
The truss had to fail for a reason. It sounds like it was overloaded. You mentioned the 1st and 2nd floor are both sagged. Does the failed truss hold up a bearing wall for the second floor? If so, you may need a structural engineer to evaluate the situation.
If you can, I would contact the truss manufacturer. They often have very long warranties and may be able to help you in this situation.
If you are determined to try this repair yourself, I would firmly brace the lower chord to the basement floor, and then use a small hydraulic bottle jack to jack the upper chord back into place, with the jack being between the lower and upper chords. Then brace the two apart with 2x4s. I would then use 1/2 inch plywood on both sides to tie the two chords together. I would glue and screw the plywood to both sides. I would use a minimum of 6 feet in length. Make sure the glue is completely set prior to removing the floor bracing.
Again, I strongly recomment this situation be looked at by a structural engineer before doing any repairs.