Tersus maintains a single view in the client at any given moment. Other views (regardless of whether or not they are in the same perspective) are not accessible.The perspective and view tabs provided by the Legacy Navigation template you're using, are links through which the user switches to another view, causing the previous view's content is removed from memory.Note that the System template which is translated in run-time to a perspective, is not considered a client-side element, which is why any process (non-display) element in it is actually executed on the server, when the application is started.
This is all part of the functionality provided by the Legacy Navigation application template. If you wish to implement a display where top-level tabs can access each other, you can do so using a tabbed pane, and perhaps base your application on the Blank View application template (see here for additional details on the differences between these templates).
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