Making listboxes interdependent

Hello,

I have an userform with many listboxes which retrieve the unique values from a big table which a master data table. In the userform I have multiple Listboxes which I would like make as interdependent as in when one listbox value is selected the other listboxes values get filtered automatically. Below I have a piece of code which does the work for the values selected in listbox 1 to automatically filter out contents in listbox 2

Private Sub ListBox1_Change()
Dim a() As Variant
Dim dic As Object
Dim i As Long, j As Long
  
  Set dic = CreateObject("Scripting.Dictionary")
  a = Sheets("MDB").Range("A2", Sheets("MDB").Range("C" & Rows.Count).End(3)).Value
  
  ListBox2.Clear
  With ListBox1
    For i = 0 To .ListCount - 1
      If .Selected(i) Then
        For j = 1 To UBound(a, 1)
          If a(j, 1) = .List(i) Then
            dic(a(j, 3)) = Empty
          End If
        Next
      End If
    Next
    If dic.Count > 0 Then ListBox2.List = Application.Transpose(dic.keys)
  End With
End Sub

https://www.mrexcel.com/board/…ent.1185098/#post-5780796

I have attached a sample file with data of 3 months for a test. Also, a screenshot of the Userform.

Thank you in advance to whomever who would render a helping hand to fix this for me.

royUK : <could you give me an example how it can be done please?

royUK : Actually, in my listboxes the option of multi-select is enabled. So when for example I choose multiple values in listbox1 (named "Source"), the values in listbox2 (named "Name of Project") gets filtered based on the selections in the listbox 1.

In the file that I have attached, I am able to achieve that (please check the attachement).

What I want to achieve is that, based on the values in listbox 1 all the other listboxes should contain only the relevant values based on the selections from listbox 1 as what happens currently to list box 2.

Also if possible, the same rule should be applied to all the listboxes as in any selection in any listbox should trigger a filtering of values in all other listboxes, thus making each one of them interdependent.

royUK : Also, the values in the listboxes are based on a table called "DynamicPath_2"

royUK : I have been quite elaborate in my explanation. To simply put, I expect my listboxes to be interdependent in terms of their selected values and finally apply the filter based on the selections. it is demonstrated in the attachement for listboxes named "Source" and "Name of Projects"

If you do not understand, thats ok, but I don't agree that my requirement and explanation are not comprehensible by anyone at all and also I stated earlier, I am just starting to work with VBA and its normal that whatever I could gather from the help of other forums and forum members, I implemented.

If you are not able to help, it would be just enough to leave a comment as such instead of keep on pointing out that my explanation is not clear or implying that I am not quite sure of my requirement

The end purpose of the userform is to effect a filter to the master data which is a table called "DynamicPath_2" located in the sheet"MDB"