Move pivot from prefab or spawn it from child

I don’t know how to ask this question.
I have a modular level generator that spawns prefabs. I have a prefabs that is 10 points long in X(figure A), so I spawn another from a gameobject position inside that prefab that is a spawn point 10 points after the origin from this prefab(point B). Having a controlled size works fine, but I want to add prefabs with different forms, they would have different sizes and their origin point would be somewhere else.

My question is, can I
a) Spawn the following prefab using a gameobject position inside such prefab. For example, where prefab A ends prefabs B begins. Something like


where the | would be the spawn point of the next prefab.

B)Move the prefab origin point so I can always spawn it from the same position without having to hard code the spawn point position for each prefab.

Thank you people!

I solved my problem. I put the editor in “show pivot” mode, moved everything inside a gameobject and aligned everything inside said gameobject. Now when I spawn a prefab it use the gameobject position as the origin point