I'm assuming what you want to do is detect when a specific tab has been clicked in your FragmentTabHost. This can be accomplished quite simply by adding a setOnTabChangedListener. Here is an example:
FragmentTabHost t = new FragmentTabHost(getActivity());
t.setOnTabChangedListener(new OnTabChangeListener() {
@Override
public void onTabChanged(String tabId) {
// TODO your actions go here
}
});
}