This down duvet feels really good.
Doesn't it feel good to have a clean house?
This massage feels good. I'm enjoying this good pain!
When you have a feeling (気持ち) that is いい (that means "good" by the way), you have a good feeling.
The reading comes from the vocab word 気持ち, so if you know that (or the vocab words 気 and 持ち you should be A-okay on this one. Maybe even feeling good about it?