Here are ways to start using Matter with others depending on whether or not they are a current Matter user.
If they're not currently a user:
Advisors: Click the + icon and enter their email to add them as an Advisor
Home: Use the composer to enter their email and Request Feedback
If they are currently a user:
Home: Request feedback, gather feedback, or give them kudos by entering their name
Advisor: Request feedback, gather feedback, or give them kudos through the (•••) overflow menu