Currently, in a 3-of-5 wallet, all 5 keys are treated as equals. While this may be fine for a majority of uses, it might not be best for all.
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 exit anymore.