Jira service desk customer list

[integrations]

Our organization is facing a huge problem using Jira Service Desk.

Whenever my agents deal with issues in service desk project, they can see the customer list page on the side bar, which is what we would want to hide so badly.

Aware that there's no such setting in the, and also tried Security Field Plugin, which is not able to solve the issue I am facing. 

We're hosting it ourselves. Just wondering if there's any way I can modify the source code?  Wondering which file I should be adjusting to hide the "customers" button ?