Adding custom UI inside of Jira Administration - User and Roles page

[Robert Bojtos]

Hi, 

I created a jira plugin from scratch with the intention of enriching the "User and Roles" page of a project. 

The end result is to have some clickable elements for each group of users that is assigned to the project on any role level, and once you click an element, you see all the users in the group.  

I've read the documentation for jira modules and web-panels seems to be what I'm looking for.

https://developer.atlassian.com/server/jira/platform/web-panel/ 

However they require a "location" so it knows where to load the new introduced UI. The problem is that I am unable to find the value to put into the "location" attribute. 

My question is: 

Is the way I'm trying to do it even possible?

If yes, how can I find the "location" for the User and Roles page?

If no, is there another way that I'm missing? 

Thank you, 
Robert