Select and create a group name using msg.payload

[jbudd]

I don't use subflows so this is mostly guesswork.

You can use a ui-control node to hide or reveal groups Disable a dropdown node on the basis of a switch node result - #11 by E1cid

So maybe you could have several groups, each with the same set of text fields.
The subflow could populate the fields in your chosen group and reveal it, hiding the others.