The ellipse is curved, its shape is adjusted, and one is reduced to the center in equal proportion. Select and trim two graphics at the same time, as shown in the following figure.
Continue to trim the graphics with rectangles to get the shape you need.
Of course, the result of direct graph Boolean operation will be a bit stiff. If necessary, you can use the shape tool to adjust the anchor points one by one until you are satisfied.
Select the adjusted graph, click Rotate again, move the center point to the lower right, you can customize it, and then change the rotation. The parameters are shown in the figure below.
The final effect.