As per the below code, I need to create a model which will have N number of "System", and each "System" will have N number of "SytemDatabase" and each "SytemDatabase" will have N number of "CoresData". This N number will come to know during the launch time of application.
Qt Code: 
  1. struct CoresData {
  2.     int m_iCoreSpeed;
  3.     bool m_bCoreAvailable;
  4. };
  5.  
  6. class SytemDatabase {
  7. public:
  8.     SytemDatabase();
  9.     bool  m_bDatabaseVisible;
  10.     int m_iDatabaseNumber;
  11.     QList<CoresData> m_listCoresData;
  12. };
  13.  
  14. class Sytem {
  15. public:
  16.     Sytem();
  17.     bool  m_bSystemAvailable;
  18.     int m_iSystemNumber;
  19.     QList<SytemDatabase> m_listSytemDatabase;
  20. };
  21.  
  22.  
  23.  
  24. class SytemTree : public QAbstractItemModel {
  25.     Q_OBJECT
  26. public:
  27.     explicit SytemTree( QObject *parent = nullptr);
  28.     ~SytemTree();
  29.     QVariant data(const QModelIndex &index, int role) const override;
  30.     Qt::ItemFlags flags(const QModelIndex &index) const override;
  31.     QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const override;
  32.     QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const override;
  33.     QModelIndex parent(const QModelIndex &index) const override;
  34.     int rowCount(const QModelIndex &parent = QModelIndex()) const override;
  35.     int columnCount(const QModelIndex &parent = QModelIndex()) const override;
  36.  
  37. private:
  38.     void addSytemDatabase(Sytem &data);
  39.     QList<Sytem> m_listSystem;
  40. };
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Currently I have designed this model using a ListModel and its working fine. Now for some reason i need to move this model to cpp side and pass that model to qml. Below is the QML code for just a reference

Qt Code: 
  1. SytemTree.append({ "iSystemNumber": systemNumber, "bSystemAvailable": false, "SytemDatabase":[{ "iDatabaseNumber": databaseNumber, "bDatabaseVisible": false,"CoresData": []}]})
  2.  
  3.         for( var lp = 0; lp < totalcoreData; ++lp) {
  4.                 SytemTree.get(systemNumber).SytemDatabase.get(iDatabaseNumber).CoresData.append({ "bCoreAvailable": true, "bCoreAvailable": true, "iCoreNumber": coreNumber})
  5.                 }
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In qml side i want to use this model as like below
Qt Code: 
  1. Repeater {
  2.                 id: repeaterRootSystem
  3.                 model: SytemTree
  4.                 delegate: Rectangle {--
  5.                 ----
  6.             }
  7.              Repeater {
  8.                 id: repeaterDatabase
  9.                 model: SytemTree.get(index).SytemDatabase
  10.                 delegate: Rectangle {---
  11.                 ---
  12.             }
  13.             Repeater {
  14.                 id: repeaterCoresData
  15.                 model: SytemTree.get(index).SytemDatabase.get(index).CoresData
  16.                 delegate: Rectangle {--
  17.                 ----
  18.             }
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I have gone through concepts QAbstractListModel, QAbstractItemModel and QAbstractTableModel. But am looking for a model like one list model, and each list element will contain a tree like structure as mentioned above in the classes. Requesting anyone to suggest how to create a model which will have tree like structure. and which QAbstractxxxxxmodel will be correct to implement this concept. and in QML side i want to access the data through the index untill coresData , same like above QML code.

Thanks in advance.