Grouping of Non-Parallel Tasks Across Arms

Task grouping creates an uninterrupted experience for participants over several tasks.    

Across many arms, Grouping defaults to support slight differences across arms. Those differences might include an intervention in one arm, but not another. Those interventions are almost always followed by tasks that are consistent across arms.
But, sometimes they are not. 
When you add groups, you end up with an odd set of tasks grouped and some outside the group. 
How do you group tasks across arms when they are tasks are quite different between those arms?
First, add your the tasks you want to group in every arm by updating your rules. Don’t worry. You’ll be removing them from the arms they don’t belong. Then group the tasks as you normally would.
Then, go back and edit the arm assignments for the tasks. Edit the rules so they are only in the appropriate arms.
You’ve now grouped non-parallel tasks across arms. The participants in both arms will get one task after another without returning to their task list.