This tool is used to correct the image from the chromatic dispersion : each color plane is slightly offset from the others, due to atmospheric refraction being different for long and short wavelengths.
Each pair of line allows to control the x and y offset for each color plane, with a text field and a slider.
Other buttons are :
The correction is usually done by offsetting red and blue planes with respect to green ; green offsets remaining at zero. This is not mandatory.