It should be sufficient to switch to a desired tab and drag&drop the element to the tab area. The tab control should become container of the element. You can check it so that you move the tab control. If the element does not move with the tab control it is not nested and so switching the tabs has no effect on it. If the element is nested and it is moving with the tab control but it is always visible when you switch tabs, it is a problem. It that case could you please tell me what version of SIM are you using and send me a screenshot or an example project file with this problem to email firstname.lastname@example.org.