Looking for a way to group Signees

I was wondering if there is any way to group signees on a document.

The situation would be where I have Party A which is actually two people and Party B which is again two people.

Party A are buying something from Party B, I would like both purchasers to sign first, and then the two vendors.

I can send it to the parties in order A1 then A2 then A3 then A4 but it would make more sense if I could send it to both A1 and A2 at once and when they have signed, have it delivered to both B1 and B2 for signature.

Is this an option in Adobe Sign?