嗨Mayank， 

默认情况下，没有OOB方法来获取单击Web部件的用户数。

By default, there is no OOB method to get the number of the users who click the web part.

您可以开发自定义代码来监控在页面中单击Web部件的用户。

You can develop the custom code to monitor who clicks the web part in the page.

更多参考：

如何在SharePoint Online中生成网页浏览报告。

How to Generate a Page View Report in SharePoint Online.

https://www.rightpoint.com/thought /2014/09/21/page-views-in-0365-sharepoint-online.aspx

祝你好运，

Sara Fan