As far as I know there isn't any such diagram the Compact and Touring are not covered at all in the Bentley Shop Manual.
For the e36/5 (compact) the only possibility I can think of is to ask the Shop Foreman of your local BMW Dealer if the BMW TIS has any info on the route of the rear washer hose. You may be surprised, they might be,
the part number is 61688360989 for REAR WIPER HOSE
from realoem.com
http://www.realoem.com/bmw/enUS/show...70#61688360989