As an example, make a document that has a animated rectangle on the main timeline. Now make a new timeline. If you change the playhead position on the main timeline and go back, the position of the rectangle is the same on the other timeline.
To clarify terminology, timelines don’t have buttons, they only have animations. Scenes or symbols contain elements and timelines.
From what I think you are describing, yes, relative timelines are the way to go. However it wouldn’t be from 0 to -100. It would be “from 0 to 0”, or to speak more to relative timelines, it becomes “from current value to 0”.