Mix flour, butter, and brown sugar together in a bowl; press into a 9x13-inch baking dish.
Bake in the preheated oven until crust is lightly browned, 12 to 15 minutes.
Sprinkle pecans and coconut over crust. Pour sweetened condensed milk over pecans and coconut.
Bake in the preheated oven until set, 25 to 30 minutes.
Heat caramels and milk together in a small saucepan over medium-low heat until smooth, 2 to 3 minutes. Pour caramel sauce over baked sweetened condensed milk. Sprinkle chocolate chips over caramel. Cool completely before cutting into bars.
