Please note, users joining Blink before June 2018 may be part of Channels. These are a discontinued feature of Blink and behave differently to chats.
When you leave (or are removed from!) a chat, you lose access to it.
It will no longer be visible to you. Its history, files and applications will no longer be accessible to you, not even through search. When a user leaves a chat or is removed, you can see a system message appear in the chat, informing you they they are no longer part of the chat.
As a chat admin, you have the power to make another user admin, or to remove a user from a chat. You can do this in the info panel on the righthand side of the chat.
The only way to regain access to a chat is to be invited again by an admin of that chat.
If you're getting too many notifications from a chat, try turning them off. This way you can stay involved in a conversation without being alerted to every new message.