You're likely to find that your report is for more than one audience. Or you can write each section strictly for the audience that would be interested in it, then use headings and section introductions to alert your audience about where to go and what to stay out of in your report. Wide variability in an audience. You may realize that, although you have an audience that fits into only one category, there is a wide variability in its background. But if you don't write to that lowest level, you lose that segment of your readers.
Most writers go for the majority of readers and sacrifice that minority that needs more help.
Others put the supplemental information in appendixes or insert cross-references to beginners' books. So you've analyzed your audience until you know them better than you know yourself. The business of writing to your audience may have a lot to do with in-born talent, intuition, and even mystery. But there are some controls you can use to have a better chance to connect with your readers. Add information readers need to understand your document.