In some instances, due to an optimization enhancement in the exported SWF file (CS4), some of the layers might be combined as a single layer. If so, you can quickly redistribute these elements onto individual layers again.
In the Camera view, select the drawing that contains elements you want to redistribute onto individual layers. To select the all the elements of the selected drawing layer, press Ctrl + A (Windows/Linux) or ⌘ + A (macOS).
Do one of the following:
From the top menu, select Drawing > Distribute to Layers.
In the Tool Properties view of the Select tool, click the Distribute to Layers button.
The number of drawing layers corresponding to the different grouped elements are created in the Timeline view. The selected elements in the original drawing layer are removed. Each element is distributed onto a new drawing layer.
Repeat the process for each drawing that contains elements to redistribute.