Microsoft Project: Filter predecessor and successor based on “Task Path” function

Microsoft Project version 2013 or later provide a function named “Task Path” to highlight the driving predecessor or successor in gantt chart but not provide a function to filter the activity.

We can create a macro to filter activity based on “Task Path” function.

Go to View -> Macros -> Visual Basic

Right click on Project Global -> Insert -> Module

Add the following code (created by Boyle) to the module

'TaskPathFilters Module
'This module includes four procedures to mark tasks according to their TaskPath
'characteristics.  A fifth procedure applies a filter to display only the marked tasks.
'The module is intended only for users of Microsoft Project 2013+, which incorporates TaskPath
'formatting of task bars.  If the applicable TaskPath formatting has not been applied,
'then no filter will be created.  VBA code developed by TMBoyle, 14Sep'18
'   1. Install all code into a new module, with "TaskPathFilters Module" above as the top line.
'   2. Assign buttons or hotkeys to the first four procedures only (the other one is called by these):
        'a. AllTaskPathFilter() - Filters all the marked task paths.
        'b. TaskPathPredecessorFilter() - Filters the marked "predecessors" of the selected task.
        'c. TaskPathDrivingPredecessorFilter() - Filters the marked "driving predecessors" of the selected task.
        'd. TaskPathSuccessorFilter() - Filters the marked "successors" of the selected task.
        'e. TaskPathDrivenSuccessorFilter() - Filters the marked "driven successors" of the selected task.
'
Public MsgBase As String, Tsel As Task
Sub AllTaskPathFilter()
    Dim t As Task
    Dim Apply As Boolean
    
    Set Tsel = ActiveCell.Task
    For Each t In ActiveProject.Tasks
        If Not t Is Nothing Then
            If (t.PathPredecessor = True) Or (t.PathDrivingPredecessor = True) Or _
                (t.PathSuccessor = True) Or (t.PathDrivenSuccessor = True) Then
                t.Marked = True
                Apply = True
            Else
                t.Marked = False
            End If
        End If
    Next t
    Tsel.Marked = "Yes"
    If Apply Then
        MarkedFilter
        MsgBox (MsgBase & "All Selected for task " & vbCrLf & _
            Tsel.ID & " - " & Tsel.Name)
    Else
        MsgBox "No Filter Applied."
    End If
End Sub
Sub TaskPathPredecessorFilter()
    Dim t As Task
    Dim Apply As Boolean
    
    Set Tsel = ActiveCell.Task
    For Each t In ActiveProject.Tasks
        If Not t Is Nothing Then
            If t.PathPredecessor = True Then
                t.Marked = True
                Apply = True
            Else
                t.Marked = False
            End If
        End If
    Next t
    Tsel.Marked = "Yes"
    If Apply Then
        MarkedFilter
        MsgBox (MsgBase & "Predecessors of task " & vbCrLf & _
            Tsel.ID & " - " & Tsel.Name)
    Else
        MsgBox "No Filter Applied."
    End If
End Sub

Sub TaskPathDrivingPredecessorFilter()
    Dim t As Task
    Dim Apply As Boolean
    
    Set Tsel = ActiveCell.Task
    For Each t In ActiveProject.Tasks
        If Not t Is Nothing Then
            If t.PathDrivingPredecessor = True Then
                t.Marked = True
                Apply = True
            Else
                t.Marked = False
            End If
        End If
    Next t
    Tsel.Marked = "Yes"
    If Apply Then
        MarkedFilter
        MsgBox (MsgBase & "Driving Predecessors of task " & vbCrLf & _
            Tsel.ID & " - " & Tsel.Name)
    Else
        MsgBox "No Filter Applied."
    End If
End Sub

Sub TaskPathSuccessorFilter()
    Dim t As Task
    Dim Apply As Boolean
    
    Set Tsel = ActiveCell.Task
    For Each t In ActiveProject.Tasks
        If Not t Is Nothing Then
            If t.PathSuccessor = True Then
                t.Marked = True
                Apply = True
            Else
                t.Marked = False
            End If
        End If
    Next t
    Tsel.Marked = "Yes"
    If Apply Then
        MarkedFilter
        MsgBox (MsgBase & "Successors of task " & vbCrLf & _
            Tsel.ID & " - " & Tsel.Name)
    Else
        MsgBox "No Filter Applied."
    End If
End Sub

Sub TaskPathDrivenSuccessorFilter()
    Dim t As Task
    Dim Apply As Boolean
    
    Set Tsel = ActiveCell.Task
    For Each t In ActiveProject.Tasks
        If Not t Is Nothing Then
            If t.PathDrivenSuccessor = True Then
                t.Marked = True
                Apply = True
            Else
                t.Marked = False
            End If
        End If
    Next t
    Tsel.Marked = "Yes"
    If Apply Then
        MarkedFilter
        MsgBox (MsgBase & "Driven Successors of task " & vbCrLf & _
            Tsel.ID & " - " & Tsel.Name)
    Else
        MsgBox "No Filter Applied."
    End If
End Sub

Sub MarkedFilter()
Dim HL As Boolean

    If MsgBox("Apply Highlighting Only?", vbYesNo) = vbYes Then
        HL = True
        MsgBase = "Highlighting TaskPath "
    Else
        MsgBase = "Filtered for TaskPath "
    End If
    On Error Resume Next
    FilterApply Name:="Marked Tasks", Highlight:=HL
    If Err.Number <> 0 Then
        FilterEdit Name:="Marked Tasks", TaskFilter:=True, Create:=True, OverwriteExisting:=True, _
           FieldName:="Marked", Test:="equals", Value:="Yes", ShowInMenu:=True, ShowSummaryTasks:=True
        FilterApply Name:="Marked Tasks", Highlight:=HL
    End If
    EditGoTo ID:=Tsel.ID
End Sub

Click Save and Close the Visual Basic window.

In Microsoft Project, we highlight the activity we want to create the driving predecessor path, and go to Format -> Task Path -> click on Driving Predecessors: