Question about tier item decks

By maddenman7, in Imperial Assault Campaign

On the campaign log, it says that after the side mission between story mission 1 and 2.

"Tier 1 & 2 items, spend xp"

In the learn to play guide it says "players draw six item cards from the current tier's Item deck."

How is this done when there are two item decks in this circumstance?

Do you draw 3 from each or is this up to the players discretion to draw a number from each deck equaling 6 total??

See the Rebel Upgrade Stage rules:

"If more than one Item deck is listed on the campaign log,

players shuffle and draw six cards from each deck."
Also if Jyn has Smuggler's Luck:
"After revealing cards from both available decks, Jyn’s player
chooses one of those decks from which to draw the extra card."

Thank you very much!