In order to provide a user access to multiple deployment areas, ensure that the user is a member of multiple groups each with an explicit deployment area assigned. See
Assigning a deployment area to a group.
It is important that any of the groups do not have "Default" deployment area selected, since that will cause the default deployment area to be automatically selected and the user will not be prompted.
For example:
A group named "GroupA" needs access to multiple deployment areas "DeploymentArea1" and "DeploymentArea2", where the default deployment area is DeploymentArea2.
To do this, assign "GroupA" one of the deployment areas, say "DeploymentArea1". Create another group, "GroupB", and assign the other deployment area "DeploymentArea2" to it.. Then add "GroupA" to "GroupB".
Now all the members in "GroupA" will have the option to select either DeploymentArea1 or DeploymentArea2 as the deployment area when logging in from the TIBCO Spotfire Analyst client.