How can I fill this hole that appear whenever I explode a poly surface and delete faces. I already tried to offset surface but it didnt delivered a nice result.
I assume you are asking about filling the gap between the inner and outer surfaces.
If the ends are co-planar then PlanarSrf may work.
Another approach would be to use Loft.
In addition to David’s suggestions, you can _Cap the outer surfaces and use the inner joined surfaces to _Trim out the centre - assuming they are planar.
If the shapes aren’t planar you can _Sweep2 to close the outer joined surfaces and either move or extend the inner surfaces to intersect with the new swept face and _Trim.