ThousandEyes dashboard widgets can be embedded directly into an AppDynamics dasboard.
To do this, simply use the URL from the Embed Widget menu in a widget that is part of an existing ThousandEyes dashboard.
Note - Only the URL is needed, not the full iframe code.
Paste the URL into an AppDynamics dashboard widget under the URL to display field in an AppDynamics widget. Make sure Security Sandbox IFrame is unchecked.