First you will have to export all the 3D Objects to Excel and create new unique Resources with the Name/User field having the value from desired 3D User Field. After importing the empty Resources from Excel to SYNCHRO Pro, you can run the following script to assign 3D to the Resources having the same Name or User Field Value -
RESOURCE ASSIGN_OBJECT(VAR 3D(SELECTED AND UFV("User Field")==$0.NAME))