Create two defects and link them
Public Sub LinkDefects()
        
' Create two defects and link them

    Dim BugF As BugFactory
    Dim Bug1 As Bug, Bug2 As Bug
' tdc is a TDConnection. The user is authenticated and
' connected to the project before this routine runs.

    Set BugF = tdc.BugFactory

' Create two new defects.
    Set Bug1 = BugF.AddItem(Null)
    Bug1.Summary = "Lydia Bennet is 15 years old."
    Bug1.Status = "New"
    Bug1.Priority = "3-High"
    Bug1.Field("BG_SEVERITY") = "3-High"
    Bug1.DetectedBy = c_qcUser
    Bug1.Field("BG_DETECTION_DATE") = Date
    Bug1.Post
    
    Set Bug2 = BugF.AddItem(Null)
    Bug2.Summary = "Mr. Bennet hides in library."
    Bug2.Status = "New"
    Bug2.Priority = "3-High"
    Bug2.Field("BG_SEVERITY") = "3-High"
    Bug2.DetectedBy = c_qcUser
    Bug2.Field("BG_DETECTION_DATE") = Date
    Bug2.Post
    '
' Link the new defects.
    Dim BugLinkF As LinkFactory
    Dim bugLink As Link
    Dim bgLinkable As ILinkable

'Cast Bug1 to ILinkable and get
' bug link factory for Bug1.
    Set bgLinkable = Bug1
    Set BugLinkF = bgLinkable.BugLinkFactory
'Create a link between Bug1, the source entity,
' and Bug2, the target entity.
    Set bugLink = BugLinkF.AddItem(Bug2)
    bugLink.LinkType = "Related"
    bugLink.Post
    
' Show the link definition.
    Dim anObj As Object
    Set anObj = bugLink.SourceEntity
    Debug.Print anObj.Summary  'Lydia Bennet is 15 years old. (Bug1)
    Set anObj = bugLink.TargetEntity
    Debug.Print anObj.Summary  'Mr. Bennet hides in library. (Bug2)
    
End Sub

Defect to defect links