Turn light bulbs in series while changing the brightness

Hello. I am very new to Home Assistant and came to ask for some help! I have 3 light bulbs, managed to put them in a group and trying to set up a behaviour for them:

  1. When changing brightness from 0% to 30% I want only one bulb turned on and slowly change brightness form 0% to 100%;

  2. When the first bulb reaches its 100% brightness I want other two bulbs to turn on (at 31% for the whole group)

  3. As brightness changes up, I want the first bulb to stay at 100% brightness, and two other to raise their to 100% when the main group brightness reaches 100%

And also I want the whole group to save its state when turned off and on.

Looks simple at first, but even experienced friends couldn’t help me!

What’s the purpose of this unusual turn-on sequence?

Also, when you create a group of lights, it’s to make it convenient to control all of them together (i.e. make all group members behave the same way, not differently). Seems to me that what you want is a script to control the turn-on sequence of all three lights (and their individual turn-on behavior).

Well, the minimum brightness of all three of them is too high for me, and I came up with that solution. I already know, that group is for controlling all the members together, and came here to ask for something different.

What should I put in the script? Could you please give me a brief exmaple?

There are several examples in the documentation link I posted. The second example shows turning on two lights in sequence. It uses a fixed time delay between the two but in your case it would be a wait_template because you want it to wait until the first light reaches 100% brightness before turning on the other lights.