I am probably teaching grandmothers in the art of egg sucking here, but...
I have a BO that relates to multiple currencies.
BO has:
psCurrency - a peer relationship to a list of currencies
scCurrencyISO3 - a short cut to the ISO currency code in psCurrency
Amount - a number field
I was today years old when I realised that I could use an attribute / shortcut to define the label of another attribute.
Label for Amount is set to <<BO.scCurrencyISO3>> and now I don't have to fiddle about with grouping attributes on forms.
Mind blown.
** Note as at 13 Oct 2021 - if you change the name of the BO AIM does not rename this in the Label**