To send your brand partners cross promotion proposals, you can click Explore Partners
on the left menu and then click on the My Partners
Here you can click on your brand partner's tile and then click explore campaigns. You will be directed to the brand profile page, where you can explore the brand partner campaigns and click on Express Interest
to send cross promotion proposals.
On this screen you will see your campaigns and promotional channels on the left, and your brand partner's campaigns and promotional channels on the right.
You can select which of your campaigns you would like your partner to promote and specify the channels on the left, while on the right, you can specify which campaigns you would promote for your brand partner along with the channels.