I am flying MIA-SFO on AA in June. The same morning, my parents are flying MIA-LAX-SFO on DL (they're SkyTeam FFs, I'm a OneWorld FF).
AA use concourse D, DL use concourse H at MIA. Is it possible for, say, my parents to go through security at D and then walk through the airside part of the terminal to concourse H? Or vice versa - for me to go through security in H and then walk all the way to D? I've never "connected" in MIA as such, but I've used it as an O&D point before so I don't know what the rules/ways are of changing concourses while airside.