How to add a Button on SUS top-right corner ( Near Log off button)

Hi Experts,

It's a bit urgent for me. Please give your valuable suggestions to achieve below scenario.

My requirement is :-

1. adding a button on top-right corner(near log-off button) of SUS screen.
2. when that button is clicked, a pop-up should appear, which shows a list of supplier IDs.
3. SUS user selects a supplier ID from this list.
4. Subsequently, PO, Invoices and other documents should be filtered out based on supplier ID selected.

Request you to help me how to achieve it technically. Thanks a lot.

Regards,

Ratnesh