Is it possible to support multiple snapshots / store a snapshot / restore from a snapshot to a state with another snapshot?
This can't be done, the snapshots are not 'tiered' such that snapshot 2 can revert back to the snapshot 1 state.

In SQL Server, database snapshots preserve the original state of each page only when it is changed in the source database. Snapshot 2 is not preserving changed pages from snapshot 1 but from the original source database.

The documentation highlights this in step 2 under "How to Revert a Database to a Database Snapshot".

Your best bet would be to copy the original database, then take a snapshot of the copied database. Run your "snapshot 2" tests against the snapshot taken of the copied database. You can then easily revert the snapshot for multiple tests and return to your pre-test state and when you're finished, simply drop the copied database. In this fashion, your original database will be unaffected by your testing.