Solved: Open page after clicking field value

field("Parent No."; Rec."Parent No.")
{
    ApplicationArea = All;

    trigger OnDrillDown()
    var
        ChildTablePage: Page ChildTablePage;
        ChildTableRecord: Record ChildTable;
    begin
        ChildTableRecord.SetRange(ChildTableRecord."Parent No.", Rec."Parent No.");
        ChildTablePage.SetTableView(ChildTableRecord);
        ChildTablePage.Run();
    end;
}