Click the number section, the next menu shows all groups where we are a member. Such a feature.
May be even better assign different bio's/profile photos for different groups - at least one set is for my contacts and another for public groups/channels.
These settings should be applied also to bugs.telegram.org and other services, so users could hide their avatar/name. Would be great if would be possible to choose a different bio for "public", so only contacts could see real name, picture and info!