Hmm, at least in my version (8.2) I am unable to format disparate expansions using any combination of name overrides and header overrides to achieve your expansions on both account and UD1 in the format you desire
A modification of my original proposal that gets close would be to switch the primary dimension to UD1 in the row block where you are defining the expansions and then applying the renaming to account. Meaning:
U1#Top:A#RevOther:Name(|MFAccountDesc|),
U1#Top:A#RevSales:Name(|MFAccountDesc|),
U1#ProcessType.Base:A#OperExpense,
U1#ProcessRank.Base:A#OperExpense
If you're on a higher version, you might play around with setting the 'Use Default Row Headers' to False, picking 1 dimension as the Header 1 Dimension Type and then testing different expansions with renames using :Name(|MFAccount|) or :Name(|MFUD1|)