Summary

In Advanced Roadmaps, we can create shared teams and easily use them in JQL queries.

Private teams can also be used, even though they don't show up in the JQL auto-complete.

Solution

Follow the steps to create a JQL with private teams:

1. Find the Team custom field ID:
   1. Go to the custom fields configuration screen (https://myjira.com/secure/admin/ViewCustomFields.jspa endpoint)
   2. Find the Team custom field
   3. Click on Actions > View
      
   4. Take note of the ID in the end of the URL. In this case, that's 10600, and the URL is the one below:

      https://myjira.com/secure/admin/ConfigureCustomField!default.jspa?customFieldId=10600
      

2. Navigate to the REST API call for one issue in the private team:

   http://myjira.com/j8131/rest/api/2/issue/KEY-123
   

3. Locate the part that looks like this:

   "customfield_<ID_from_before>":"<team_ID>"
   For example:

   "customfield_10600":"5"

4. Now we can use this private team ID in JQL queries, such as

   project = "my project" AND Team = 5