Your VBA code would have to loop through all the sub shapes and set that formula up, any time the group gets a new shape. The format of the formula would be just like your example, so it wouldn't be too hard to do:
SubShp.CellsSRC(visSectionFirstComponent,0,2).FormulaU = "Sheet." & Cstr(ParShp.ID) & "!Geometry1.NoShow"
or something like that, where that's in a loop for each SubShp in ParShp.Shapes...