The possibility to create group helpers is a great feature.
I can build groups of devices, for example lamps.
It would be helpful to see or search, a member of which group(s) a device or other entity is.
Meanwhile i have found a work around:
Go to “developper tools”, tab “states”
Filter the groups if possible
Search in the results for the entity name
Group members are shown in the column “attributes”.
I hope, there will be solution for easier access.
I have placed a feature request 8 months ago.