SAP Cloud SDK : Create Entry from ABSL (Root and Node Level) in Custom BO

Hi Experts,

Scenario: I want to create the data from ABSL code with root as well as node level data.

I have created the Custom BO with the below elements:

businessobject CustomAllActivity {

[Label("ID")] [AlternativeKey] element ID : ID;

[Label("Description")] [AlternativeKey] element Desc : LANGUAGEINDEPENDENT_Text;

[Label("Start Date")] element StartDate : Date;

[Label("End Date")] element EndDate : Date;

Node allActivity [0,n]  {

          element ActivityID : BusinessTransactionDocumentID;                              // Activity ID from Standard BO

          element ActivityName : EXTENDED_Name;                                              // Activity Name / Desccription  from Standard BO

          element ActivityType :  LANGUAGEINDEPENDENT_Text;                    // Activity Type(PhoneCall, Task, Email etc...) from Standard BO

          [DependentObject(TextCollection)] [MultipleTexts] node MyNote;             // Activity Notes from Standard BO

     }

}

I want to get all the Activity ( Phone Call , Task , Appointment , Email ) and Store into the Custom BO node entry based on the Date..

I have created the Object-based screen for this business object.

I want when user click on New from OWL under the QA screen user can able to enter the "Description , StartData and EndDate" and save the entry based on start date and end date i need to fire a query on date of creation in activity and based on that store data under the custom entry in node allActivity 

Please refer the above screen for more details.

at last i want the code to save the root level as well as node level data in same time on custom action or standard event(AfterModify , OnSave etc....)

Kindly help me to solve this issue.

Many Thanks,

Mithun