JIRA Service Desk - customer requests visible to other customers

I am using JIRA Service Desk (2.5.9) on our server and I am looking for a solution to Jira 6.4 to allow customers to view requests created by other customers belonging to the same organisation. Unfortunately, I can’t upgrade right now to JIRA 7 (I saw it is possible in that version).

Is there maybe any other solution that you can think of? Maybe a plugin that would work with this version of JIRA? I don’t want to give our customers the possibility that is described in this link so: What are request participants? | Jira Service Management Cloud | Atlassian Support

Thank you so much!

I regret to inform you that there’s currently no solution in sight for JIRA 6.4.
We developed a plugin called Collective Issue View for Service Desk, which you can find at the Atlassian Marketplace: Atlassian Marketplace
Please note that this plugin runs only under JIRA 7.0 or higher. It is not planned to develop the plugin for lower versions as the Atlassian Support End for JIRA 6.4 is dated for March 17th, 2017, which you can see here: Atlassian Support End of Life Policy | Atlassian Support | Atlassian Documentation

there is a simple but cool solution. The customer has (even if the
support has ran out already) at every time the right to upgrade to the
last version which was accessible at the last day of his running
support. He can have a look at the JIRA versions and look, which version
was available that day and just take this one to install. If support
ran out one month ago, he is capable to upgrade to JIRA 7, what should
clear his problems.