Freshsales allows you to associate contacts of multiple companies in a single deal.

Say you create a deal with the Account Knight& co. This deal invloves collaboration of two contacts Zach from the same company and Kiera from Madison Inc. You need to,

1. Click the deal quick add button.
2. Add deal overlay appears.
3. Add a Deal name and the other required information.
4. Choose the Account name as Knight& co. 
5. Search for Zach and the contact from Knight& co. gets listed. You can add this to the contact. When you are searching, Freshsales provides the email and account details to let you choose the relevant contact.
6. Repeat the same for Kiera. 
7. Click Save.