How close this window in Home?

In Home > Automations I clicked on an action (terminology?) that I no longer used and a window popped up to set the light level but no way to close it. Edit: After force quitting I retried it and added the intermediate step.

I have to admit that Home continues to baffle me. For example, why can't I click or right click on Night Light to find out what device it is?

Clicking on Night Light brings this up and this is the window that can't be closed.