(() => {
    
    const roleRight = [
        {
            "Id": 1,
            "RoleId": 1,
            "RightId": 1
        },
        {
            "Id": 2,
            "RoleId": 1,
            "RightId": 2
        },
        {
            "Id": 3,
            "RoleId": 2,
            "RightId": 2
        },
        {
            "Id": 4,
            "RoleId": 3,
            "RightId": 1
        },
    ];

    const roles = [
        {
            "Id": 1,
            "Name": "Администратор",
        },
        {
            "Id": 2,
            "Name": "Модератор",
        },
        {
            "Id": 3,
            "Name": "Пользователь",
        },
    ];

    const rights = [
        {
            "Id": 1,
            "Name": "Контакты - Просмотр",
        },
        {
            "Id": 2,
            "Name": "Контакты - Редактирование",
        }
    ];

    const usersRoles = (() => {
        const dictionaries = {
            roles,
            rights
        };
        
        const dictionariesIndexed = Object.keys(dictionaries).reduce((res, key) => {
            res[key] = {};
            
            dictionaries[key].forEach(item => {
                res[key][item.Id] = item;
            });
            
            return res;
        }, {});
        
        const result = roleRight.reduce((res, item) => {
            res[item.RoleId] = {
                Id: item.RoleId,
                Name: dictionariesIndexed.roles[item.RoleId].Name,
                Rights: []
            };
            
            return res;
        }, {});
        
        roleRight.forEach(item => {
            const roleId = item.RoleId;
            const rightId = item.RightId;
            
            result[item.RoleId].Rights.push({
                Id: item.RightId,
                Name: dictionariesIndexed.rights[item.RightId].Name
            });
        });
        
        return Object.values(result);
    })();

    console.log(usersRoles);
    
})();

const roleRight = [
  {
    Id: 1,
    RoleId: 1,
    RightId: 1
  },
  {
    Id: 2,
    RoleId: 1,
    RightId: 2
  },
  {
    Id: 3,
    RoleId: 2,
    RightId: 2
  },
  {
    Id: 4,
    RoleId: 3,
    RightId: 1
  }
];

const roles = [
  {
    Id: 1,
    Name: "Администратор"
  },
  {
    Id: 2,
    Name: "Модератор"
  },
  {
    Id: 3,
    Name: "Пользователь"
  }
];

const rights = [
  {
    Id: 1,
    Name: "Контакты - Просмотр"
  },
  {
    Id: 2,
    Name: "Контакты - Редактирование"
  }
];

console.log(
  roles.map(role => {
    return {
      ...role,
      right: roleRight
        .filter(item => item.RoleId === role.Id)
        .map(item => rights.find(right => right.Id === item.RightId))
    };
  })
);