Change the stacking order using the Layers panel

The stacking order of objects corresponds to the hierarchy of items in the Layers panel. Artwork at the top of the Layers panel is at the front of the stacking order, while artwork at the bottom of the Layers panel is at the back of the stacking order. Within a layer, objects are also stacked hierarchically. By creating multiple layers in your artwork, you can control how overlapping objects are displayed.

Do any of the following:

Drag the item’s name and release the mouse button when black insertion marks appear in the desired position. Black insertion marks appear either between two other items in the panel or on the left and right edges of a layer or group. Items that are released over a layer or group are moved above all other objects in the item.
Click in the item’s selection column (between the target button and the scroll bar), drag the selection color box to a different item’s selection color box, and release the mouse button. If the item’s selection color box is dragged to an object, the item is moved above the object; if it’s dragged to a layer or group, the item is moved above all other objects in the layer or group.
To reverse the order of items in the Layers panel, hold down Ctrl (Windows) or Command (Mac OS) and click the names of the items whose order you want to reverse. The items must be at the same level in the layer hierarchy. For example, you can select two top-level layers, but you cannot select two paths that are in different layers. Then select Reverse Order from the Layers panel menu.

Note: You cannot move a path, group, or collective element to the top position in the Layers panel—only layers can reside at the top of the layer hierarchy.