You need to make the a frame for each group within the larger frame

|=====================|
|                     |
| |=================| |
| |  Radio 1 (X)    | |
| |  Radio 2 (X)    | |
| |=================| |
|                     |
| |=================| |
| |  Radio 3 (X)    | |
| |  Radio 4 (X)    | |
| |=================| |
|                     |
|=====================|                          


That should resove your problem.