Each Program Tag Database in ControlLogix is separate. Only the Controller Scope tag database can be used any any routine, in any program, in any task.
If you have tags that need to be used in multiple Programs, they must be Controller scope.
It's easy to change a tag from Program Scope to Controller Scope; create an identical tag in Controller Scope, then delete the tag from the Program Scope database. All the references will follow the tag to the Controller scope tag database.