You can establish and monitor relationships between 2 elements of the same type in the current model without copying the elements.
When a monitored element changes, a warning message displays.
You establish relationships between pairs of corresponding elements. For example, select a grid line, and then select another grid line to form a relationship between them. You cannot monitor unlike pairs, such as a grid line and a level. If you select an opening in a wall or floor, you can monitor other openings or inserts.
To monitor elements in the current model without copying
Coordinate panel
Copy/Monitor drop-down
Tools panel
The monitor icon
displays next to the element to indicate that it has a relationship with another element.

An architectural column and a structural column (plan view) with a monitoring relationship
Copy/Monitor panel
If you modify one of the elements in a pair, a warning indicates that a monitored element has changed. These warnings also display in a coordination review.