How can I use a single action to trigger animations in multiple objects? I have a problem to do with animations in blender, namely that I need to set up two different object's animations within one Action, and then another object separately in another action, so  that when I import my file into Unity there are two separate animations; one of the two parts moving, and the other of one part (which is the parent of the other two parts) rotating.
The problem is that when I try to do this and set up keyframes for one object, if I then add the other object to that action it will just snap to those same keyframes, instead of being able to have its animation edited separately.
So my question is how can I set up an animation with multiple objects holding their own keyframes (like I would normally do with a regular keyframe animation) but with the ability to make a separate unique animation for a different object as well?
I've seen some things in other similar questions to do with the NLA editor I think and merging two separate actions together into one but I can't find any actual information on whether this is what I need to do and if so how to do it.

Sorry if this isn't very well worded, please tell me if you need any clarification.

EDIT: Ok so I have found out how to use the NLA editor to solve my first problem (I instead created two different actions with both parts moving separately and then added them both into the NLA editor) However now when I try to make a new action to rotate another part of my object it is automatically added to the NLA editor as the same animation, but I need it to be completely separate, how can I accomplish this? It seems there is no way to remove it from the NLA editor once it's there it's rather frustrating...
Ok I solved this myself and in fact for my problem I didn't even need to use the action editor or NLA editor, all I needed to do was make the bits I wanted as separate animations happen at different points on the timeline, and then when I put the object into unity I could select those frames from the animation to be separate animations, so the whole thing was a lot less complicated than I was trying to make it.
If anyone else has information on how to do this in blender though please add an answer because I'm sure not everyone who comes across this question will be intending on putting their animation into unity and so may still need another answer