Clutch problem
 

I have a 1993 BMW 325is and the clutch pedal went to the floor I added more fluid and it seems to come back. I notice for some months that I saw some fluid on the drive way and never could figure out where it was coming form. So is there a way to determine if it is the slave cyclinder bad or the master cyclinder is back or both and what to do?

change both. sounds like the slave is bad

Yea I'd say for sure the slave due to the fact that the master is actually inside the car on the clutch pedal. I replaced both of mine when my master went and i think they were pretty cheap.

I have recently replaced both the master and slave clutch cylinders...using pirate Chinese parts as OEM are much too expensive.
Now works fine but even with my small hands I battled to replace the master cylinder although I think it is worse on the RHD cars such as I have as compared to the LHD E30s in the USA.

Mine did the same thing. I was not leaking fluid but mine fell to the floor, turns out it was the master cylinder. BTW just a heads up bmw seattle sent me 2 master cyl. gaskets so let me know if you'd like the one I didn't use. might save you a few bucks.

Clutch
 

It was the slave it took me about 1 1/2 to replace mostly cause too my time and my car was hard to jack up

The master cylinder (for the clutch) will leak inside the car. Master and slave are easy to rebuild. Depending on model the clutch will share fliud from the brake system..