Option Explicit
Sub TEST()
Dim Brr, Y, i&, T1$, T2$, xR As Range
Set Y = CreateObject("Scripting.Dictionary")
Set xR = Range([B1], Cells(Rows.Count, "A").End(xlUp)): Brr = xR
For i = 1 To UBound(Brr)
T1 = Brr(i, 1): T2 = Brr(i, 2)
If Y(T1) = "" Then
Y(T1) = Y.Count: Brr(Y(T1), 1) = T1: Brr(Y(T1), 2) = T2
ElseIf InStr(Brr(Y(T1), 2), T2) = 0 Then
Brr(Y(T1), 2) = Brr(Y(T1), 2) & "/" & T2
End If
Next
xR.Offset(0, 9).ClearContents: xR.Offset(0, 9).Resize(Y.Count, 2) = Brr
Set Y = Nothing: Set xR = Nothing: Erase Brr
End Sub