About the force of an object in 3D grid Refinements case

Dear all,
I am currently working on the refinement for a 3d object in 3D grid Refinements case. In this case, I only obtained the force of the object under the time of the coarsest grid in calculation loop, but how to obtain the force of the object under the time step of the finest grid level (every time step in finest grid level)? please~