I'm doing this through MB Views, so using the mb. format for the following PHP commands.
Let me start by clarifying a couple things, to save time:
- the answer is not in this group (at least it is not findable).
- there is a post that says this can be done using rwmb_get_field_settings() but that does not do what I need (it does not return the current saved value of fields).
Via a MetaBox View, I can get the current field label and / or value using rwmb_the_value() or rwmb_get_the_value and post ID.
However, this does not work if the field is within a group.
We can call this a bug, as there is no reason the field ID should not be accessible directly, whether or not it is part of a group. Otherwise using groups is not really worthwhile (which would be a shame as they are good for organisation).
Perhaps the answer to this question can also be added to the rwmb_the_value() / rwmb_get_the_value() documentation.