Hi Divya!
You can leverage the following to return the Catalog requests with a pending action for a user:
select distinct request_id from usm_request_pending_action where status in (1,5) and ( ( user_id = 'spadmin' ) or ( group_id in ( 'test group' ,'test group 2') ) )
If you are not interested in pending actions assigned to group(s) the user is part of you can remove that part of the condition, otherwise you can specify a particular group(s) or all groups as included in the 'User Group Membership' section of the user's profile in the Catalog UI.
Thanks,
Jason