Dear,
In IA01, task list for equipment creation, the task list group is created against single equipment number.
I think you can not have an equipment task list group number against multiple equipment numbers.
For a single equipment number if you want to have multiple equipment task lists, that is possible and they will be under same group number with increasing group counter numbers.
In the Equipment Task List: Task list overview screen, go to Edit -> New Entries, and create the other task lists for the same equipment.
Best Regards.
Rajen