The docs refer to Group Start and Group End. I don’t see these in available Pro Form elements. Has it been replaced with Options Group?
This is an old, legacy function in the old way of doing forms with Bricksforge. With the Nestable approach, you can just use Bricks Elements like Blocks to group your form 
Many thanks - I woke up this morning and thought “ah, that must be for the old Pro Form because a container will do the job in nestable.”
Would be really grateful if you’re able to look at the other queries I posted yesterday.