I don't think this is created from a gradient. As mentioned in comments it seems to just be a simple geometric pattern consisting of a lot of circles on top of some rectangles.
You could probably use all sorts of transform magic to make it easier, but here I just want to show you how to draw the pattern with the mouse and keyboard using Ellipse Tool, Rectangle Tool and taking advantage of Smart Guides.
It's easier to show with an animation than to explain in words. The animation is real-time so as you see, it doesn't take long to make.
Duplicate the pattern and change the colors to make something similar to the example you've posted.