from that description i don’t know of a “system” that does that.
it would actually help to know what your game/app is trying to achieve. to get a better idea.
maybe you can check “factories”, but that’s a pattern not a system. (and i usually don’t like factories much).
though from your description it seems you look for a pattern more than a system.
also check “subsystems”.
you can have a base class for your actors, and when they get spawned they get a ref to the subsystem and “auto register” and when they get destroyed they unregister.
that’s pretty nice because sometimes you might want to de/register while it’s still alive.
maybe because you use a pool, or maybe because you use de/activate. (like hiding and stuff).
the subystem can (and i’d recommend) have delegates for OnAdd and OnRemove of these actors.
the ui binds to those delegates and adds/removes ui widgets accordingly.
those ui widgets can be a widget blueprint for each item.
i’d recommend have a widget that’s not a button, but has a button. so you can extend later on.