Maybe after a circle is spawned you set the circle to spawn random sprites at locations inside the Area of the circle.
If the area of your circle is 200 then the radius is 100.
So maybe something like this:
Event>>>Circle on screen
Action>>> Create object on positions (circle.width/2 + random(-100,100),circle.height/2 + random(-100,100)
I think this will spawn enemies within the radius of the circle and then add or subtract a couple of distances within the circle. The -100 to 100 is the interval I guess, so once the position of half the circle is decided the system will either subtract or add a value between -100 to 100 to the center point of the circle giving your a random spot within the circle.
You could probably replace the value of 100 with the radius that you want for your circle
Any ideas how you'd make enemies randomly spawn within a circular (or any irregular) shape?
I don't want to hard code spawning locations if possible.