I am not able to find the nested instance as i am new to sketchup. I am attaching my file. Could anyone please help on this. The model has to be made a solid group to print.
Construction Airpod.skp (221.0 KB)
Fixed Airpod.skp (211.9 KB)
Try that. Not sure what exactly you are going for here, you had what looked like a keychain ring added to one side that was a separate component. I exploded that and merged it with the side of the larger piece it was embedded in.
Thank you!! The problem i am facing is i am not able to make everything together a solid group
What are you wanting to accomplish exactly? To print these three objects on a 3D printer? To export each one as a separate .stl and print them one at a time? What is the small rectangle for? Can you describe more what you are wanting?
A solid group can only contain raw geometry, as soon as something is grouped within a group it is no-longer considered a solid and solid inspector will highlight the nested object.

That was really helpful for me. Thanks for your effort.
I want to print this model in 3d printer. Small rectangle was just for support to flip, sorry never mind. I just want to make sure this model will print in the 3d printer. I am attaching the workfile i did. I have tried to complete it but not sure if this is printable. Please ignore the orginal airpod case.
Construction Airpod~.skp (329.5 KB)