New to repair - is this repairable?  

Looks like a tinted clear finish that has been chipped or scratched off. I think lacquer is the most commonly used finish with a tint and it looks like this when scratched off (very distinct margins). There is a way to dissolve the finish with acetone or lacquer thinner and kind of smear it around to cover the bare area. I have never had any success with this the few times I've tried it but I'm not a professional refinisher.

Don't sand the entire door, then you'll have to come up with a new finish that matches the rest of the piece! That will be much trickier than getting this one little area fixed.

Use Light Oak marker, gently daub and blot with tissue.