RE: How Certificate Renewal works
Hi Nitish,
This can be achieved by setting a time limit on HR Parameters. For detials please see the screenshot below-

Once you specify a time limit here, this setup starts notifying manager about the records that are going to expire in next 15 days
So for ex, Josephine - the manager sees a tile below on My Team tab

when he drills down he sees a detailed view-

where as for an employee him/herself, it shows as below-

1. First one tells employee about the certificate that's gonna expire in 8 days , and
2. Talks about an expired certificate
So, basically whenever the Renewal flag is raised in the setup against any certificate, it starts showing up on Manager screen like below-

I hope this helps!