A map element that inherits from another man element is indicated with a black arrow icon decorator (the same decorator that's used to indicate inheritance of an element in the structure editor). You can go to the inherited map element by right-clicking on the child map element and selecting Go to Inherited Map Element.
If the map element in the child map is modified from the parent map, this is indicated by a gold triangle icon decorator (the same decorator used for the corresponding reason on the structure editor). If you wish to remove the changes in the child map element you can select it and right click and select Revert to Inherited Map Element. You can revert either the selected element, or all of the descendant map elements.