If you have full ALM (vs. ALM Quality Center Edition or ALM Starter Edition) the answer is yes. Full ALM supports cross project reporting through the Dashboard module, while enforcing the authorization rules established for users of projects (if you aren't authorized to access a project, you can't pull it into a report built in another project).
If you don't have full ALM, then that feature is not available to you. You would have to use external tools to extract the data you want for your report.
(Opinions and information contained in this post are wholly my own and do not reflect the opinions of my employer.)