Floor truss in crawlspace, holding up first floor. 14” depth. About 20 ft span is my estimate, with about half of it sitting on concrete block, acting as rim joist.
Gently remove the old plates and jack or screw the bottom chord tight, then install steel plates with screws. Don't trust the original gussets to hold if you pound them back into place. The new plates should be at least as large and thick as the originals.
1" truss-head screws would be appropriate. Put screws in every hole with good wood behind it.
Jack the bottom chord back up into position and then hammer the nail plate back into the wood, then reinforce that join by nailing metal strap over it.
Just the straight strap from a coil, run some down each side of the diagonal and across the bottom of the truss, put clouts in all the accessable holes.