Possible Clues:

• Military advisory gp
• Advisory group established by HST
• The JCS Chairman is its military advisor
• Foreign policy grp. whose letters are hiding in 'foreign relations committee'
• Dr. Fiona Hill's former grp
• Advisory group to POTUS
• Advisory grp. to the president
• Grp. that meets in the Situation Room
• Defense advisory grp
• Gp. of foreign policy advisers