On the Draw toolbar, click Connector
In the Connector ribbon bar, set the line start and end terminators.
Pass the pointer over the target object to highlight the potential keypoints or connect points.
The connector can attach at keypoints on the symbol or predefined connect points. The connect points appear as red circles with Xs. The keypoints appear as gray circles with Xs.
Click the symbol to place the connector.
The connector attaches to the connect point that is nearest to the point that you clicked. Otherwise, the connector attaches to a keypoint or any point along the elements in the symbol.