Try to represent inside the made circle one more smaller circle:



The layer’s parameters: Blending Options>Gradient Overlay



Gradient’s parameters:

 



Make a copy of the earlier made blue circle and use after that the Free Transform option to make the copy smaller and to place it on the central part of the element:

 



As we have described earlier, we have to combine in a group all the layers, composing those three small circles (keep pressed the Ctrl button to mark out the corresponding layers and make a left mouse’s button click to take the layers down on Create a new group option). Make eight copies of the last made group and select the Free Transform option to change the copies’ sizes and to place them as it is indicated on the next picture:



Next we’ll work with the first group.



Make seven copies of the group and select again the Free Transform application to change the copies’ sizes if necessary, placing them the way presented below: