I have a user who created 4 requests. On 3 of them she changed the Primary Contact to be her supervisor. She cannot see them in her "Requests I've Submitted" tab, but he can see them in his (even though he did not actually submit them)
If we had filtering options there, I could help her set up a filter where "entered by" is herself. I created a report as a work-around, but it would be nicer to have filter options there.