Memoir '44 FAQ wrote:
Q. Can I use Infiltrators in combination with Behind Enemy Lines to battle twice and move a single Infantry unit 12 hexes (or more with Take Ground)?
A. No. These cards do not stack.
Q. If you play Infiltrators (Combat Deck) or Behind Enemy Lines, then use the Heat of Battle to get an extra attack, does the additional die from Infiltrators/Behind Enemy Lines carry over?
A. Yes. Heat of Battle allows the unit, after a successful Close Assault, to Take Ground and battle again with the bonus.
The Memoir FAQ can be found at: https://www.daysofwonder.com/memoir44/en/advanced-play/faq/