"Concentric" means various shapes or things that share the same center point, like circles within circles or rings that have a common middle. Full definition
Noland became celebrated in the 1950s for his series of concentric circles in a dazzling array of colours; not, like the paintings of Jasper Johns, targets, but circles as a simple geometric form that could demonstrate an infinite number of colour combinations. (theguardian.com)
Avoid performing a back extension during the upward concentric phase of the squat. (onnit.com)
They are installed in concentric rings in the center of the gallery floor. (hamptonsarthub.com)