@jackberg2012, You haven't explained what you are trying to achieve so it is not clear why you want to mirror everything - including the Footprints - whilst keeping it on the same side of the PCB. With the exception of pin headers for mounting things like Arduino Shields stacked on the bottom of a PCB (with their top layer facing the bottom layer of the PCB), it makes no sense to flip Footprints without also swapping sides of the PCB. Simply mirroring a Footprint whilst keeping it on the same side of the PCB results in a Footprint-pad to physical-package mismatch. Rotating a Footprint or swapping from top to bottom sides or vice versa makes sense but simple mirroring does not.

@andyfierman Hi andy. I did flip the bottom layer for milling process on a single side PCB. I assume the "Flip Horizontal" will just flip everything, but's not the case. Thank's for your reply. my regards.