I completely all 4 endings for FO4. I first did a bunch of live streaming that did a lot of exploration, questing, and I ended the series by getting help from the Brotherhood and then siding with the Institute. This is in my Adventures playlist.
I then went back and completed the endings for the Railroad, Minutemen, and finally the Brotherhood. Each of these start at the halfway point during the Molecular Level quest; where you select which faction to help you gain access to the Institute.
I have now restarted the game from the beginning. Since I left off at level 56, I decided to cheat and bump my level up to that. I don't want to go through all the level building again, but I don't like to go beyond the level I earned. I actually took a little loss since I was halfway to 57--no biggie! The reason for this restart is because I found out there is a 5th ending. An ending where the Brotherhood, Railroad, and Minutemen are allies and won't attack each other. It requires a specific path that you have to follow and I'm going to try and do all those steps. Since I'm now playing EQ again, progress in this is going to be a little slower for awhile.