3 story condo. 3 diff residences

Thought I had posted this way back in 2017 but can't find it. House is 3 story with a 4th level deck. Lower level is common area. Lev 2 and 3 separate residences. Common, 1, 2 are all standalone Ra2. This is family owned brothers and family. No renters. They are now discussing having app control. Before you say it, no 3rd party. Level two still has cabinet full of unlanded wires. A/V guy is out of the loop. Common level controls outside and stairway time clocks. Help me clear my brain please. My options as I see it. 1 They make a email IE beachhouse@**** and combine all to one account. again it's fam so don't think they are worried about privacy. 2 one level has account for their level and common. Other level has account for their level only. Issue is the time clocks and loads on that system. They aren't always there at the same time and may want to control lights as needed. There is mass amounts of cat wiring but not sure if any connect between levels. Ideas would be helpful assuming wiring between levels and/or no wiring.

Since they are brothers and, clearly on speaking terms, you could create 3 separate homes under 1 account. They would be common, level 2, and level 3. The negative is if you are in level 2 and want to control the common areas you have to switch homes in the app. I don't believe you can have a RA2 system assigned to 2 accounts.

Is it possible to get them all in 1 system? If the layout is structured properly, it should be easy enough to avoid accidentally turning lights on/off in the other residence.