Your phrasing is quite strange, as Smart Lists and Custom Objects are wildly different concepts!
- Smart Lists are dynamic collections of person records based on simple or complex filters. A person can be a member of unlimited Smart Lists, as SL membership is computed on the fly.
- Custom Objects are (in the broadest sense) groups of fields with a united business purpose. Each CO record is related to one person record.* A person can have multiple COs of the same type, as well as multiple COs of different types.
A Smart List can therefore include people who have Custom Object records with certain types + field values. But a Smart List will never be a Custom Object.
Can you explain exactly how you imagine Custom Object records intersecting with dynamic content?
* yes, deliberately simplifying by leaving out junction-leaf config
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