You can do this using the InStr and Mid functions.
Use the InStr function to find the occurrences of the / and then use Mid to get the part of the string that you are interested in.
Try this:
Function ExtractFirstPartOfPath(path as String) as String
Dim first, second as Integer
first = InStr(path, "/")
second = InStr(first + 1, path, "/")
ExtractFirstPartOfPath = Mid(path, first + 1, second - first - 1)
End Function
This function will produce the desired results.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…