Just tested this in 6.3.1 and the tab container pages can be set to visibible based on a boolean attribute. Open the properties of the tab page, select the Edit button on the visibility. In the dialog now set the tick mark at the top to true and select the attributes from the list below that. Be aware however that the tab page and therefore the container needs to be placed inside the dataview. If you do not have your tab container in a dataview and e.g. only have dataviews on your tab pages you will not be able to select the attributes, as the page visibility needs to have a context to select the attributes from. Otherwise the modeler would never know which entity the attributes need to be selected from and these can't be selected from dataviews on the pages themselves.