Translate a group of Geometries

Hey !

In my C# script, i want to translate a bunch of Geometries (curves, Brep, Surf) all together. I've grouped them up in GH before inputting them in the C# component -> I've a group list

I assume i'll have to use *.Transform(Transform.Translation(Vector3d)); later on my geometries

Since I cannot convert my Group in GeometryBase I'm a bit lost :v

If anyone knows a way, i'd be glad hearing it !
Thx for your time

MacGros