Preheat the oven to 375°F.
In a large bowl, combine the shredded chicken, mozzarella cheese, cream cheese, mayonnaise, garlic powder, onion powder, salt, black pepper, and chopped parsley. Mix until well combined.
Slice the French bread in half lengthwise and place it on a baking sheet.
In a small bowl, mix the softened butter and minced garlic. Spread this mixture evenly over the cut sides of the French bread.
Spoon the chicken and cheese mixture onto the bottom half of the bread, spreading it evenly. Place the top half of the bread over the filling.
Bake in the preheated oven for 15-20 minutes, or until the bread is golden and the cheese is melted.
Remove from the oven, let it cool for a few minutes, then slice into individual sandwiches. Serve warm.