1. Create an UI Wizard connected to your XML spec for the global change.
  2. Within the VB code, use a ResetDataSource on the _sourcecampaignid_valuechanged & _targetcampaignid_valuechanged with the field _sourcesubpriorityid & _targetsubpriorityid.
An example of the code needed is as follows:

Public Class UIFGlobalChangeToRevenueCampaignTagsByDesignationUIModel

    Private Sub UIFGlobalChangeToRevenueCampaignTagsByDesignationUIModel_Loaded(ByVal sender As Object, ByVal e As Blackbaud.AppFx.UIModeling.Core.LoadedEventArgs) Handles Me.Loaded
    End Sub

    Private Sub _sourcecampaignid_ValueChanged(sender As Object, e As AppFx.UIModeling.Core.ValueChangedEventArgs) Handles _sourcecampaignid.ValueChanged
        _sourcesubpriorityid.ResetDataSource()
    End Sub

    Private Sub _targetcampaignid_ValueChanged(sender As Object, e As AppFx.UIModeling.Core.ValueChangedEventArgs) Handles _targetcampaignid.ValueChanged
        _targetsubpriorityid.ResetDataSource()
    End Sub

End Class