I have a string, `alpha/beta/charlie/delta`

I'm trying to extract out the string `alpha/beta` including the forward slash. 

I'm able to accomplish this with split and joining the first and second result, but I feel like a regex might be better suited.

Depending on how many slashes there are as well will determine how many strings I need to grab, e.g. if there's 4 slashes get the first two strings, if there's 5, then grab first three. Again, my problem is extracting the slash with the string.