When pressing ctrl-b on an element that is covered by a PsiPolyVariantReference, the possible target locations are only displayed using the value returned from PsiNamedElement.getName() for each resolve result. In the not too uncommon case that the resolved elements all have the same name, it's impossible to distinguish the elements in the list. See the attached screenshot.
The list should show the return value from each element's getPresentation().getLocationString() - if available - next to its name or use some other means to be able to identify each element in the list.