Heat a smoker to 250°F. In a small bowl, stir together the softened cream cheese, green chiles, and corn until evenly combined. Set the filling aside.
In a large bowl, mix the ground beef, egg, breadcrumbs, milk, onion, chili powder, cumin, salt, and black pepper. Combine gently just until the mixture holds together.
Lay a large piece of parchment on the counter. Pat the meat mixture into a rectangle about ½ inch thick. Spread the cream cheese mixture down the center, leaving a border around the edges.
Use the parchment to fold the meat over the filling, then pinch the seams and ends closed. Shape into a loaf and place it seam-side down on a smoker-safe tray.
Brush the top and sides with half of the barbecue sauce. Smoke until the center reaches 160°F, checking the temperature with an instant-read thermometer.
Brush the remaining barbecue sauce over the loaf during the final 10 minutes of smoking. Remove the meatloaf and let it rest for 10 minutes before slicing.