Here's mine. From other fittings used on the car, I'd say the plastic... "Flare nut" piece needs to be gently pryed out from the bell housing so the plastic body( piece with the bleed nut) can be fully seated. Then the little hold clip goes in.
I bought my car used and was loosing coolant... Turns out previous engine drop the heater core hoses( same design as this here hydrolic connection) never got fully seated and was about 14k km before they shook loose enough to leak...