Placement of two geometries using different method

I have a parameterized geometry placed inside a box using G4PVParameterised methods. I want to place another geomtry (say G4Tubs) inside same box using G4PVPlacement method. However when I do so, It gives error

userDetector->Construct() start.

-------- EEEE ------- G4Exception-START -------- EEEE -------
*** G4Exception : GeomMgt0002
issued by : G4LogicalVolume::AddDaughter()
ERROR - Attempt to place a volume in a mother volume
already containing a replicated volume.
A volume can either contain several placements
or a unique replica or parameterised volume !
Mother logical volume: phantomLogical
Placing volume: PlexiPhysical
Replica or parameterised volume must be the only daughter!

*** Fatal Exception *** core dump ***
**** Track information is not available at this moment
**** Step information is not available at this moment

-------- EEEE -------- G4Exception-END --------- EEEE -------
Ofcourse the other method is to place G4tubs outside this box, But then it will be away from the phantom. Is there a way to place T4Tubs geometry near phantom inside the box?

Hi @pradeepsingh,

Are all of the volumes you are currently defining physical volumes that have a material? or are some of the volumes just there to assist you with scoring and data output? (i.e. is your first parameterized volume a voxelized scoring grid, or something else?).

In general I am not aware of a way to place volumes within parameterised volumes. But if some of your volumes are there as a scoring grid then they could be implemented in a Parallel World in Geant4 and that may be a potential solution to your problem.