A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 15 April 2009
Related Cards: Ambush Text Limited: Target one of your unbowed Personalities: Create a battlefield (not at any province). Assign your Personality to attack there. Assign another player’s target Personality to defend there, even if bowed. No other units may move there. Fight a battle there. After it ends, lose 5 Honor.
No Hiding Place Text Reaction: Before you target a Ranged Attack from one of your attacking cards: The Ranged Attack has -1 and may target a card even if it is in the Defender’s home.
During a battle created by Ambush, can No Hiding Place be used by an attacking card in that battle?
A player, 16 April 2009
You should probably have posted this in the Rules Question forum. I don't see why No Hiding Place wouldn't be allowed, so long as you can generate a ranged attack. Same thing with a Chuda Hankyu.
Zen Faulkes (rules official), 16 April 2009
During a battle created by Ambush, can No Hiding Place be used by an attacking card in that battle?
Yes.