You can add a Matrix report to a Zoho CRM dashboard. This wasn't always the case, since dashboards used to only support Summary reports, but Zoho CRM has since added Matrix report support to dashboards as well.

How to do it

1. Create your Matrix report. Go to Reports, then New Report, choose your module and select Matrix as the report type. Set your row grouping, column grouping, and the value you want aggregated in each cell, for example Deal Owner as rows, Close Month as columns, and Sum of Amount as the value.
2. Save the report. Choose a folder, name it, add a description, and save.
3. Open or create a dashboard. Click Add next to Dashboards, or open an existing dashboard you want to add this to.
4. Add a component. Click Add Component, choose Get From Report, and select your saved Matrix report.
5. Choose a chart type. Pick the visualisation that best represents your two-dimensional data, such as a stacked bar chart, and configure its settings.

Why Matrix reports are useful for dashboards

Unlike a Summary report, which groups data along a single dimension, a Matrix report groups by two dimensions at once, rows and columns, with an aggregated value in each cell. This makes it well suited to questions like revenue by rep by month, deal count by stage by territory, or activity volume by type by week, where a single-dimension Summary report wouldn't show you the full picture.