Yes, what you need to do is deal the finishing blow with Tifa on 95 enemies.

If you want a quick fix, Go to the forests nearby Fort Condor. Most of the time you'll encounter packs of 5 enemies. They'll all die if you use a Choco/Mog. Count the enemies you've killed if you have to. Sometimes it feels like you've killed 200 enemies even though you've only killed 70.

I see you are at Cosmo Canyon, the only place nearby with many enemies in one fight I can think of is at the end of the railroad tracks near Corel. If you walk around at the right place there should often be a fight with a Cockatrice and three mushrooms, and sometimes battles with 5 mushrooms.