To target your upper butt, you can do these two exercises
1, Lying hip abduction with bent knee, lie on your side and use a weight plate or a dumbbell on the side of your leg
Do this exercise slow with control and squeeze in the top position.
When you are coming down to start position again,stop 1-2 cm to avoid knee to knee touch,because otherwise you will rest
in between reps and that is not something you should do here.
2, I call it “The frog bridge”, Lie on your back with your legs bent and place your feet together (see pic 2 a).
The raise your hips up while you keep your feet together during the whole movement.
When you come down, stop 1-2 cm off the floor and the raise your hips up again and so on.
This one is tough, and you can start out with your body weight at first.
Whenever you get stronger, place a weight plate on your hips,or a barbell.
I suggest high reps for each exercise 15-20 reps,whenever you get stronger you can do them heavier.
Because it is a small muscle group and most of us have weak medius and minius, it is wise to find muscle contact first
and do them light, full control,slowly and squeeze.
Also if you are a runner/sprinter, you should definitely target your gluteus medius/minimus and strength this area to help stabilize your hips and save your knees.
You can do these at home or in the gym.