Glass material reflection

Hi, I am a super beginner and need your help.

I tried to make the glass sphere like this.

From this GIF, The sphere includes some colored balls.
[FONT=“Segoe UI”]
I made new material from glass and slim tutorial, but the sphere reflects just environment.
I am not sure how to reflect the inside colors.

Please give me any hints or ideas!

(if someone could answer in Japanese, much better!