Lets assume there are 5 users (alice, bob, carol, david and eva). You can create a 3-of-5 multisig using miniscript in which alice and bob should be a part of 3 users that sign the spending transaction. The third signer could be anyone among the remaining.
It was possible to test miniscript and visually see different policies using bdk
playground but it doesn't exist anymore.
Damn, I don't really know miniscript that much but I think I should revive this. Maybe I'll put it on my old site (notatether.com)