Thank you for reaching out and welcome to the community.
I tried recreating the scenario you mentioned as follows:
I have created two tables: Staff and Certification.
The Staff Member column in the staff table is in contact format.
The certification table has a staff column which is a rowlink and picklist format with source table as Staff.
A screen has been created and a column list added to display a list of all certifications for logged-in users, using a filter expression under the data tab on the far right of the screen. Below is the expression I am using.
Below is how it shows the certification of logged in user.
Hope this is helpful. Feel free to reach out to us if you have any further question.