The custom dashboard feature in AppDynamics allows you to display a specific set of metrics and data points on one screen. You can use custom dashboards to present selected metrics for a user who only needs a relatively narrow or focused view of the data. You can also share custom dashboards with other users and stakeholders.

According to the [Custom Dashboards - AppDynamics], some of the advantages of the custom dashboard feature are:

It makes drill down across tiers seamless: You can use the grid layout type to create a flexible layout that is easy to rearrange on the canvas. The grid layout also scales in size when viewed on mobile devices. You can also use the absolute layout type to control width and height and the exact placement of widgets on the canvas.

It monitors metrics of interest: You can add widgets from various categories, such as application, server, database, performance, events, and so on. You can also customize the widget properties panel to configure the widget settings, such as title, description, color scheme, time range, auto-refresh interval, and so on.

It schedules dashboard as a report: You can export your custom dashboard as a PDF or HTML report that you can send by email or save as a file. You can also schedule your custom dashboard to run periodically using cron expressions.

Therefore,A(It makes drill down across tiers seamless),C(It monitors metrics of interest), andE(It schedules dashboard as a report) are three advantages of the custom dashboard feature.Reference:

[Custom Dashboards - AppDynamics]

[Create and Manage Custom Dashboards and Templates - AppDynamics]

Custom Dashboard Permissions - docs.appdynamics.com