A problem I was having was that even though you could successfully create a new Task Force (Crtl-F4), create branches under it and assign Task Groups to it, in the Naval Organization window tab (F12), when you looked at the Task Force Organization window, the Task Group was still assigned to the Fleet Headquarters Task Force. So when you select it under the branch it is assigned in the Naval Organization window tab and look at the Details and Special Orders area in the top left, the Task Force drop down shows it still being assigned to the Fleet Headquarters Task Force. The solution: in the Initiative area below the Task Force drop down there is a Set button.
1. Select the Task Group that you have assigned to the branch under the new Task Force.
2. In the Task Force drop down, change the Task Force to the new Task Force that you have created.
3. Push the Set button in the Initiative area.
Your Task Group under your new branch of your new Task Force should now show up correctly in the Task Force Organizations (Crtl-F4) window and whenever you select it in the Task Groups (F12) Naval Organizations Tab, the correct Task Force will show up in the Task Force drop down upper left corner of the Details and Special Orders area.