I have a handful of zwave lights that I have configured into nested groups. My groups yaml is:
upstairs_lights:
name: "Upstairs Lights"
view: no
entities:
- light.kitchen_sink_level
- light.dining_room_level
- light.living_room_lamp_level
sunroom_lights:
name: "Sunroom Lights"
view: no
entities:
- light.sunroom_door_level
- light.sunroom_corner_level
downstairs_lights:
name: "Downstairs Lights"
view: no
entities:
- light.playroom_level
light_groups_all:
name: "Lights"
view: no
entities:
- group.upstairs_lights
- group.sunroom_lights
- group.downstairs_lights
This produces a state card that looks like this, but when I click on the card to expand it, it looks like this.
The three groups that are supposed to be in the top level group are there, but for some reason the switches that are a member of the upstairs_light group (the first one in the entities list for the top level group) also show up, along with the zwave attribute data for the first member of the upstairs_lights group ( kitchen sink). Interestingly enough, the dimmer slider causes all lights to dim to the same level.