Within the ArcGIS Desktop environment and ideally using geodatabase feature classes you can setup multiple hyperlinks to a single feature using the concept of dynamic hyperlinks. There isn't a dependency on having to use an attribute field to supply the hyperlink targets. It would be huge if this same concept could be pulled off using a service inside a web map developed in ArcGIS Online. In both ArcGIS Desktop (when setting up a dynamic hyperlink) and ArcGIS Online (if the dynamic hyperlink concept were to be implemented) it would also be nice to be able to to give a particular url provided as a hyperlink target a simplier/descriptive name. Potentially long and ugly urls although perhaps have useful information need to be simply described to make them more effective.