VBA Loop through unique values in range based on criteria

As part of my project, I'm stuck with the following.

I need to be able to loop through each unique set of values in a Worksheet, where the criteria is met.

In VBA, I need to get the maximum number of rows where the value in Column C is Yellow.

I also need to be able to loop through each unique value in Column B, where the value in Column C is Yellow.

I think the first part can be achieved with the following:

MaxCells = WorksheetFunction.CountIfs(Worksheets("Location Groups").Range("C:C"), "Yellow")

I guess I then need to do a loop from 1 to MaxCells. But that loop then also needs to do something (for the sake of this example, it could just be a MsgBox with the unique cell value) based on each unique value in Column B where the value in Column C is also Yellow.

In conclusion, a loop with three iterations, because there are only three unique values (Cell 1, Cell 2 and Cell 3) which also match Yellow.

Using Collection is an option.

Option Explicit
Sub Demo()
    Dim objCol As New Collection, rngData As Range
    Dim i As Long, sKey
    Dim arrData
    Set rngData = Range("A1").CurrentRegion
    arrData = rngData.Value
    On Error Resume Next
    For i = LBound(arrData) + 1 To UBound(arrData)
        sKey = arrData(i, 3)
        If sKey = "Yellow" Then
            objCol.Add arrData(i, 2), CStr(arrData(i, 2))
        End If
    Next i
    On Error GoTo 0
    ' print to VBE Immediate Window, change to MsgBox if needed
    If objCol.Count = 0 Then
        Debug.Print "No matching vlaues"
    Else
        Debug.Print "Total Yellow: " & objCol.Count
        For Each sKey In objCol
            Debug.Print sKey ' print to VBE Immediate Window
            ' your code '
        Next
    End If
End Sub