The Drawing Explorer window is your friend, become familiar with it.
In the case of your cloud shape, it is indeed grouped. So, don't ungroup it. Only unfortunate things will happen. All of the controls are at the top level shape. If you open the shapesheet, activate the formula tracing function, then click on one of the control points. For the formula tracing, choose Dependents, that is, items that depend upon the selected cell. So, if you click on a control point, it will show that an item in sheet.2 is dependent upon the control point. Well, as the control points move the line shapes, that must be where the line is. Open the shapesheet for sheet.2. You will find 8 geometry sections, one for each line. This will be where you add lines...each needing it's own geometry section. So, add geometry sections as needed. Mimic the existing sections. Now go to the toplevel shapesheet. Add your control point, and then add formula similar to existing control points, but now for the new geometry section.
That should do it.
Wapperdude