After your event, you're automatically connected to your group members through Timeleft Connect. You can also send Impressions — positive compliments to the people you met.
Impressions
Go to My Events, tap your completed event, and select a group member to send them a compliment. If both of you send each other an Impression, you'll be notified of the mutual match.
To remove an auto-connection or block someone
Go to Connections, find the person, tap the ••• menu, and select Remove Connection or Block User.
See: How Do I Block or Remove Someone?