If you want to leave a group, just click onto the settings icon. You find it in the upper right corner of the video meeting group. The following window appears:
Now click on Leave group. Due to this action, your user avatar vanishes from the owners’ board. Therefore, the initial group has not been deleted by yourself, you only removed yourself.
Summarily it is a simple concept. If you have added a person to your group, only the invited person can delete itself from the group. If you want to get rid of people with whom you are sharing a group with, delete the whole group and create a new one.
Everything clear so far? 😉