I'm not aware that you can bulk update. You right click on each resource and update the location. It is easier after the first time in that the second , third etc re-open at same location as the first, but I don't see a way to just bulk update.
As long as your dependencies are grouped, you could create an Alias pointing to the group. This way, you'll only have to change the Alias' path when the group has been moved.
Best regards,
Cyril Dellenbach (Micro) | QA Support Artist | Adobe
An alias won't help you now but could in the future. If your resource links had been pointing to an alias, then when you moved your files you would just need to update the alias and to Designer it would look no different.
It is a good workaround, however it would be more useful if the links worked in a similar way to InDesign where if you move your source images you get a similar warning triangle. But when you update one link in the document, InDesign relinks the rest in the same folder automatically.