You can use xpath for this. On your listview, add the xpath constraining the Regions shown to only those “preferred” by the user. The xpath would be something like:
// show the regions preferred by the current user
[MyFirstModule.Region_Account__Preferred = '[%CurrentUser%]']
Alternative to Conner's approach would be to use the Listview Controls widget – that one allows you to add various filters with a default value. It has the advantage over the Xpath approach that people can still uncheck the filter and see the entire result set, instead of only the filtered result set.