Does anyone knows how the filestream folder structure works?
I found it.

SELECT
    [o].[name] AS [Table],
    [cp].[name] AS [Column],
    [p].[partition_number] AS [Partition],
    [r].[rsguid] AS [Rowset GUID],
    [rs].[colguid] AS [Column GUID]
FROM sys.sysrowsets [r] CROSS APPLY sys.sysrscols [rs]
JOIN sys.partitions [p]
    ON [rs].[rsid] = [p].[partition_id]
JOIN sys.objects [o]
    ON [o].[object_id] = [p].[object_id]
JOIN sys.syscolpars [cp]
    ON [cp].[colid] = [rs].[rscolid]
WHERE [rs].[colguid] IS NOT NULL
    AND [o].[object_id] = [cp].[id]
    AND [r].[rsguid] IS NOT NULL
    AND [r].[rowsetid] = [rs].[rsid];
GO