Can we restrict certain user accounts only to a particular cat_item in Service Portal,?

[Rajkumar Sakth2]

We have created user accounts (Virtual Acc) based on their Company and Country they are supporting thru a cat_item.

So user of this particular cat_item, will have two user accounts, AD one and newly created one Virtual acc.

Now when user selects, these virtual accounts also visible in every cat_item, inc, req, change everywhere.

How to make them invisible these accounts, except that cat_item.?

[Rajkumar Sakth2]

For reporting purpose. Being service provider they work for a company, But they serve for another.

While reporting the correct company has to be mapped for them, which they are supporting.

[Rajkumar Sakth2]

@Ankur Bawiskar  - Any suggestions please..