I have an entity type with three fields: FieldA, FieldB and FieldC. FieldA and FieldB have the type "Entity". They link to another entity with two fields. FieldC is a string which I need to automatic concatenate FieldA and FieldB. I use this formula.
v1(data, context) { return data.FieldA + " - " + data.FieldB; }
This works as intended, but since the fields are entities, it only returns the EntityId. I now need to get the fields inside the entity, such as data.FieldA.thisCatField. Is this possible?
As of now this is not possibly - or more precisely, would be extremely difficult because you would have to do REST calls to get the data etc.
The form itself also never needs additional fields so for performance reasons it never actually gets them. As of now there is no built-in mechanism that retrieves the entire entities for the form.
My guess is this won't be on the priorities for quite a while. I suggest you try another approach.