No, you can't replace just this one piece. It looks to be part of the front cover/frame. You'll likely have to disassemble the device, including the front panel, and install a replacement. This may result in additional issues, such as damage to the hardware. I would suggest using a case to "cover" the damage rather than risking further damage that is not repairable.If someone could reply with additional information about this I would appreciate it too. I did the same thing to my T-Mobile Galaxy S5 and would like to replace it to it wouldn't look all scratched up anymore, the rest of the phone is perfect still.
Jason