On the group chat's "Chat Details" page, you can adjust various settings:
Group Management: View group members, modify the group chat name, set the group avatar, set your nickname in the group, invite people to the group chat, view the group announcement.
Join verification (when on, newcomers need owner/admin confirmation before joining). See Why can’t I enter after joining? How to turn on join verification.
Chat Settings: Set the chat background, pin the chat to the top, set message do-not-disturb, save the group to contacts.
Privacy and Security: Enable "Burn After Reading" (currently unavailable), enable "Screenshot Notification" (currently unavailable), disable private chat among group members (Admin function), allow new members to view chat history (Admin function), scheduled group message cleanup (currently unavailable).
Record Management: Search chat content (searchable by group member, pictures/videos, files, links, etc.), clear chat history.
Exit/Report: Delete and exit the group chat or report the group.