MDM Catalog items Masking

Hi gurus ,

I want to display selective catalog items to different sets of users in SRM.

For this , I used Masks in MDM Catalog and corresponding Webservice ID in SRM.

I created 2 mask id  in MDM and assigned a few catalog items to each of these two Masks.

I checked in MDMSRM_CATALOG_ITEMS table in MDM Console. The Mask ID field is not available.

Can anyone please help me with the relation between the Mask MDM table and Catalog Items Table.   

I need a column which is common between Mask table and Catalog items table.

Thanks,

Paramesh