You can have mined materials shipped between outposts, but that’s about all I really know. I only just discovered greenhouses and the way you unlock them is so convoluted. There could be other mechanics that I’m unaware of, but I think you can only ship the raw materials between your outposts.

I never got that far into settlement building in FO4, so I’m not 100% sure the comparison is 1:1, but you can build interstellar cargo links that move raw materials (and maybe manufactured doo-dads, not sure yet) from one outpost to another. I imagine you could have a few “feeder” outposts all sending mats to one “builder” outpost.