Get a listing of snapshot data files
You can identify database snapshots in sys.databases by the column source_database_id being not null.

Join it to sys.master_files and you're done:

SELECT mf.database_id,
    dbs.source_database_id,
    mf.type_desc,
    mf.name, 
    mf.physical_name
FROM sys.master_files AS mf
INNER JOIN sys.databases AS dbs
    ON mf.database_id = dbs.database_id
WHERE source_database_id IS NOT NULL


In case you need to filter for one specific source database, you can add that predicate to the WHERE clause.