Feature similar to nesting composition?

[Sidereus Group]

Is it possible to precompose and nest one cloud .ai into another? Or even have a few artboards with precompositions that then get nested together in other artboards?

Sorry if this is a repeat post, maybe I'm using the wrong words here but if you know After Effects...it would just be so nice to have something similar in Illustrator! Even Google Docs has a similar feature with inserting charts from Sheets, now so I'm guessing I just need to be pointed in the right direction.

[Monika Gause]

Symbols?

Placing assets from the CC library?

Placing Ai files into AI files?

If those do not help, please describe better.