I'd have to guess it's outside of the transmission (a good thing) and likely having to do with the hydraulic linkage between the clutch pedal and slave cylinder. The master and slave clutch cylinders are a closed assembly that Jeep sells as a pre-assembled & bled hydraulic system that is likely what would be the fix for your problem.
I'd remove the two bolts that hold the slave cylinder to the transmission bell housing and lift the slave cylinder off so you can watch its piston that pushes against the clutch fork inside as someone steps on the clutch pedal. Is the piston going in/out smoothly and does it push outward with considerable force as the clutch pedal is stepped on? It should. No worries if the piston falls out of the slave cylinder, just reinsert it and it'll be fine. Just don't let it fall inside the bell housing.
No guarantees of course, your problem could certainly be caused by the clutch mechanism inside the bell housing but this is sure a lot easier to check first.