It is possible to draw a connector between two Symbols in a Flow Chart Model but not in an Organization Chart Model.
To draw a connector in the Flow Chart:
1. Click on the Symbol until the add element controls appear.
2. Click and hold down in the center of that Symbol.
3. Drag to the center of the Symbol you want to connect.
Workarounds for the Organization Chart:
1. Try ungrouping the Chart by selecting the Chart and choosing Ungroup from the Arrange menu. This will transform the Organization Chart into a drawing so that connectors can be drawn between any object. The disadvantage is that the you will no longer be able to use Organization Chart commands, because you now have just the graphic representation of that Organization Chart.
2. Try drawing a line with the drawing tools. This line will not be associated with the two Elements it is connecting but if drawn carefully will appear to be a connector.
Organization Charts do not allow connectors to be added since all possible organizational structures can be achieved using the add element controls (the arrows that appear around a Element when you click on it).