One of them should be your oil return to sump/block m8

The only one I've ever used is the baileys one,it's got 2 ports on the top which is where your breather pipes go too,original breather and rocker cover breather.
Then 2 ports on the bottom,a small one which is the oil return,and a big one which you just leave to vent to atmosphere.
With the baileys fitting kit you get all the pipe work you need,including the adaptor for the side of block under exhaust manifold where the oil returns too out of breather tank.
I think by your description you have only got one part of a breather system,sounds like you've only got the oil/air separator
Pretty sure Spec-R and GGR use a separate oil/air separator then a tank on the inner wing.
If you leave that pipe to atmosphere I'm pretty sure you will have oil all over the place!!!!
Get a pic up of it m8,will be able to tell for sure then