NSSegmentedControl + NSImageNameGoLeftTemplate + NSImageNameGoRightTemplate (これらの一部 (ほとんど?) はペン先で指定できます)
[self.segmentedControl setSegmentCount:2];
self.segmentedControl.segmentStyle = NSSegmentStyleSeparated;
[[self.segmentedControl cell] setTrackingMode:NSSegmentSwitchTrackingMomentary];
[self.segmentedControl setImage:[NSImage imageNamed:NSImageNameGoLeftTemplate] forSegment:0];
[self.segmentedControl setImage:[NSImage imageNamed:NSImageNameGoRightTemplate] forSegment:1];
[[self.segmentedControl cell] setTag:0 forSegment:0];
[[self.segmentedControl cell] setTag:1 forSegment:1];
[self.segmentedControl setWidth:23.0 forSegment:0];
[self.segmentedControl setWidth:23.0 forSegment:1];
[self.segmentedControl setEnabled:YES forSegment:0];
[self.segmentedControl setEnabled:YES forSegment:1];
[self.segmentedControl sizeToFit];
NSImages はここに文書化されています:
System-Provided Images for Use in Controls