In the previous Chap.  6 , we studied the multi-target fencing via adaptive controller, where the dynamics of the targets are always limited to cluster together. Such kind of scenario inevitably limits the application of the designed controller. A straightforward idea is to form a big circle of robots to fence the small circle formed by the target. However, there still exists some challenging scenarios where the targets may be scattered at different positions, which motivates the fencing controller design via flexible subgrouping and ordering in this chapter. In what follows, we will introduce the related background.