Different result with the same search keyword on search all files

Question

Am having some problem with search (number 3 in picture below).

I have two users, one from country A and another from Country B

When country A do a search on search all files, for eg testing file, he get a certain result.

But when same search is performed by country B, a different result is obtained.

Why does the same search having same profile in different locations return different results? Any possible causes?

Thanks for your reply.