Wheel Within a Wheel

The last time a puzzle included these miniature half-quads, they stood on their own. This time they’re paired with full-size quadruples, so the smaller circles describe one of two cells, and the larger circles describe two, three, or all four of four cells.

Rules:
Normal Sudoku rules apply.
Digits within circles appear at least once in the two or four cells touching the circle.

Estimated difficulty: 1 out of 5