The Layers section of the tab allows for the visualisation of data within the map to be adjusted. The Show/Hide Legend option will display the Legend for the mapping interface if required.
The Custom Layers option will allow for the selection of user created mapping layers. Further information on custom layers can be found in the section titled Creating Custom Layers. The Refresh Map option will update the map with any changes that have been made to the database while the mapping interface has been open.