Squat (ankles and hips)
Level 1. Resting squat, progress to 50% bodyweight.
Level 2. Single leg resting squat (bottom of the pistol).
Level 3. Bottom of the pistol transitioning to balancing on the ball of the foot.
Level 4. Overhead squat on the balls of the feet, flat over head squat
Level 5. Head to floor squat.
Lateral & Adductors
Be gentle with them!
Squat first.
The stronger your squats are the better your lateral splits are likely to be.
Level 1. Deep squats with widening stance, horse stance.
Level 2. Pistol with leg abducted.
Level 3. Straddle straight leg good mornings.
Level 4. Seated to chest to floor transitions.
Level 5. Side bends, Straddle side bends, Chest to floor pancake
Pancake and adductor gains are relatively easy to make from here.