The default TLspSelectController
shows a pop-up when a user clicks on a location on the map while holding down the Alt key.

The pop-up allows the user to indicate which objects must be selected. This is convenient when multiple objects overlap in the clicked spot.
This functionality is provided by the
TLspPopupMenuSelectionCandidateHandler
installed on the
TLspSelectControllerModel
.
See the class reference documentation for an overview of the customization options.