This really depends on how deep the damage goes.  I would first try sanding the area to see how far you have to go to get bamboo that is not water stained.  You will then need to replace the finish layer.  If the bamboo is stained it will be much harder to get the stain to match, but is the fnish is a clear urethane, or something similar, this should be pretty easy.  Probably won't look perfect, but close enough.  If all else fails, replace the boards.

If the damaged plank is close to the edge of the room you can simply disassemble the floor to the damaged plank and replace it and reinstall the other planks. It is a more difficult situation if the plank is in the middle of the room or a hard to reach area. If this is the case, you should contact the manufacturer for more specific instructions based on your individual situation. It is often recommended that you leave these cases to a professional installer as special tools may be needed.

You're welcome.