get FROM address within internal tx

[novaknole]

contractA calls contractB which calls contractC which then emits the event Executed(id).

I want to know who called contractC. using the transaction.from gives the address that initiated tx initially - i.e it returns EOA address. Is it possible to derive contractB ?

I know I can use tracing, but those APIs require archival nodes which I don't have access to. Is there any other way ?

Importantly, OZ's governor doesn't seem to emit msg.sender from its events, so how do they figure out who executed/canceled/queued the proposals ?