Plan on the campaign and AO maps

Draw the AOs on a greyed-out campaign map, then plan each one on a detailed map of its own with a layer per phase, drawn into the leaders' pack.

Admin, or Unit Leader with the unit role Web — a campaign page → Maps and areas of operations, or a mission's Maps card

How to do it

On the campaign page press Make the campaign map. It opens in the map editor, greyed out like a covered Arma map.
Put the map on its terrain (Map settings). Pick the AO tool, choose Rectangle, Ellipse or Freehand, and draw each area of operations: it turns clear, with a border in a colour no other AO is using. Type its name straight away — it shows in a tab of that colour at the AO's top-left corner.
Press Save. Every AO you drew is now one of the campaign's AOs, listed on the campaign page.
Back on the campaign page press Make its map beside an AO. Its map starts on the same terrain, greyed out everywhere but that AO, and one layer for every phase you gave that AO in a mission's Orders step.
Draw each phase on its own layer — the layer picker above the map — and save.
Download the Leaders' pack: each phase drawn on its layer is in it as an ops trace, cropped to the phase and the AO.

The map and the planner keep each other up to date. Rename an AO on the map and it is renamed in the planner; delete its outline and the AO goes, unless phases are fought in it or its own map has drawings, when it is kept and its outline put back. An AO added on the campaign page appears on the map as a clear box to move into place.
Overlapping AOs merge into one clear area, and stay easy to tell apart: each has its own border colour and its name in its own corner. The campaign page shows a key of every AO and its colour beside the map. Change an AO's colour with the swatches when it is selected. Its Arma marker uses that colour too, and its own map takes it when the map is made. Map settings switches the grey off or changes its strength.
The layers keep up with the planner: a new AO gets an outline, a renamed phase or mission renames its layer, and a phase moved to another AO or deleted loses its layer — unless something is drawn on it, which is kept.
A trace shows its own phase plus every layer that belongs to no phase, such as Plan or an enemy layer you add, so draw shared things there.
A map holds 12 layers, so an AO with more phases than fit says so; delete a layer you no longer need in the editor.
If you have the map open in the editor while you change phases in the wizard, your next save there puts the old layer names back. Opening the map from the planner again fixes them.
Removing an AO removes its map. Deleting a campaign deletes its maps.