How to use the group node:

First of all you must made your shape with the cut or branch cut oriented to the local Z axis and the origin in the center of the geometry as this:

Once finished the geometry you must create a new material and, in the node editor, add a pricipled BDFS shader if nedeed, add a new  Group->CitricMaterial and connect as the image.

Slide the skin fit value to adjust the skin at the correct position and define the other parameters as you want. Done!

Parameters:

skinLight: Main color of the fruit

skinVariation: Secondary color of the fruit.

skinDark: Dots color.

pulpLight: Main color of the pulp`.

pulpDark: Secondary color of the pulp.

skin fit: Value to adjust the skin to the border of the shape, approximately the radius of the shape.

skin fit width: Value to define the width of the external skin.

white skin width: The width of the internal white area of the skin.

white center width: The size of the white central area.

segments: the number of segments of the pulp.