I want to add my custom columns, and I also want to add some popups on those columns in Jenkins dashboard.
How does one add new columns, which are not present in job's configuration page?
you can use the Jenkins Dashboard View to add the layout of your choice. The page says:
The dashboard view comes with a number of portlets that you can configure your view with
so you can add top, bottom, or column portlets as you seee fit.
I wish that was possible, but it seems there's nothing yet. However, I found a decent workaround: you can select column 'Project Description'. Of course, in the project description you can write anything. That includes html code, so for example, you can use that to include links in your dashboard.