Under the Surinder Singh ruling, an EU citizen can choose to be treated under EU freedom of movement law in his or her own country after having exercised freedom of movement in another EU country.
This is reflected in EU documents. For example (emphasis added):
if you are an EU citizen and have never lived in another EU country only national rules will apply..
However, materials from Germany seem to omit the possibility for Germans to be treated under EU law after living elsewhere in the EU. For example:
Familienangehörige von Deutschen bekommen keine Aufenthaltskarte nach dem Freizügigkeitsgesetz.... [translation: Family members of Germans cannot get a residence card according to the freedom of movement law....]
Does Germany in fact allow Germans to bring their family members to Germany under freedom of movement when they've lived elsewhere in the EU? If so, is there an official source where this information is available?