C++ init a class member inside a subclass constructor init list

Question

Is there a way to init the member of a class inside the initialisation list of one of its subclasses ? let me explain, since it is way easier to visualise like that:

Inside a class I have a bitfield struct

class bitFieldInterface{

struct dataBlock{
uint32_t engineDataRPM : s_engineDataRPM .size;
uint32_t engineDataInstantConsumption : s_InstantConsumption.size;
...
uint32_t vehicleGpsLocation : s_vehicleGEneralInfoGpsLocation.size;
uint32_t vehicleGpsSpeed : s_vehicleGeneralInfoGpsSpeed.size;
...
uint32_t vehicleInfoDimensionX : s_vehicleInfoDimensionX .size;
uint32_t vehicleInfoDimensionY : s_vehicleInfoDimensionY .size;
...
} m_dataBlock;

}

in total, there are over 40 distinct fields.

I could just init them all in the constructor init list:

bitFieldInterface() :
m_dataBlock.engineDataRPM{s_engineDataRPM.defaultValue},
m_dataBlock.engineDataInstantConsumption{s_engineDataInstantConsumption.defaultValue},
...
m_dataBlock.vehicleGpsLocation{s_vehicleGpsLocation.defaultValue},
m_dataBlock.vehicleGpsSpeed{s_vehicleGpsSpeed.defaultValue},
...
m_dataBlock.vehicleInfoDimensionX{s_vehicleInfoDimensionX.defaultValue},
m_dataBlock.vehicleInfoDimensionY{s_vehicleInfoDimensionY.defaultValue},
...
{}

but since there are different categories I wanted to add more structure to my code and divide them into subclasses like so:

class EngineData
class vehicleGps
class vehicleInfo
...

and inside each class constructor initialize the corresponding fields of the main class EngineData():

m_dataBlock.engineDataRPM{s_engineDataRPM.defaultValue},
m_dataBlock.engineDataInstantConsumption{s_engineDataInstantConsumption.defaultValue},
...
{}

vehicleGps():

m_dataBlock.vehicleGpsLocation{s_vehicleGpsLocation.defaultValue},
m_dataBlock.vehicleGpsSpeed{s_vehicleGpsSpeed.defaultValue},
...
{}

and in the main class I would just call each constructor: bitFieldInterface():

EngineData{},
vehicleGps{},
vehicleInfo{},
...
{}

is there a way to do this, while keeping the m_dataBlock inside the bitFieldInterface class ?