Take a look at the other areas of the hose where there are similar connections. If this is a 380 (180, 280), the mender nut goes onto the fitting or backwash valve first (narrow end first) then the hose is pushed on and the nut tightened onto the hose. It just has to be snug and there are no real threads cut into the hose.

It is similar with the 360 EXCEPT that the nuts tighten on while turned to the left (counter-clockwise).