In a map I'm making I'm using a bunker selection system, similar to the transport selection system but with a bunker instead of an overlord/dropship/shuttle.
It seems it uses all my units because the "Bring" command in my triggers detects units in bunkers. Is there a trigger that does not?

you cannot "move/teleport" units out of the bunker., I think

but maybe try to give the unit to a computer player. that should only work with unloaded units.

Try having the bunker on low ground and surround the bunker in high ground terrain and then detect when the units are on high ground. For the detection location, uncheck the low ground elevation box.

Bring exactly 0 versus at most 0 are different
One includes units in the bunker and one doesn't. I can't remember which is which though.

Guys, I mean that you unload units to choose do to stuff, like use potions and equip stuff.

This map, made by me, should help you somewhat.

Bunker Detection

When a unit enters a bunker, or a transport unit for that matter, it can be detected anywheres inside that unit. For instance, I have a 1 by 1 pixel location directly in the center of the bunker in my map. Just by that, I can detect when a unit "Terran Marine" enters the bunker.

This can work both ways. Either detect when the unit is inside the bunker via the bring trigger detecting if the unit is inside the small location, or you can detect when the unit is not inside the small location, which is centered in the middle of the bunker. Either way works.

Thank you!

Thats what I'm here for. No problem.

At most 0 doesn't include units in the bunker. I'm using that fact in my map currently! It works awesomely.

Lol, I used this exact system in Random Quest RPG, I can send you the map if you like, it's not finished, but a lot of it works, I used one bunker for transformations, and the other for potions and items

Right, that's the one.
Its been a long time since I needed it.