Compliance vs marketing again.... if we are advertising a money market account and we have various tiers available but our ad is only about one particular tier, do we have to list all other possible tiers, minimum balances, and APY?

All tiers must be included. Here is an excerpt from the commentary to Reg DD section 230.8:

(b) Permissible rates
1. Tiered-rate accounts. An advertisement for a tiered-rate account
that states an annual percentage yield must also state the annual
percentage yield for each tier, along with corresponding minimum balance
requirements. Any interest rates stated must appear in conjunction with
the applicable annual percentage yields for each tier.

Banks with tiered rate accounts often include the most attractive rates in the body of the ad, and list information about the other tiers in the mouseprint. But all tiers must be included somewhere in the ad.