Is it possible to view custom reports for a custom segment of my users?

Segments will work within your custom reports the same way they work within the standard Matomo reports. You can apply any of the +100 segments to custom reports.

Moreover, configuring a custom report allows you to set filters that refine your view of the data. For example, you can select dimensions like « Country » and specify that you want to focus on visitors who accessed your website via a mobile device. This level of detail provides you with a more targeted and insightful analysis.