Memory scanning, 6M, 10M, channel isolation during scanning
The FT-8900 does not have banks into which memory channels can be isolated. It also does not have band scanning for memory channels (would have been nice... but it's just not part of the design of that radio).

To get some isolation for memory scanning, use Preferential Memory Scan.. page 40 of the manual for the radio...As for the programmer, set Skip to PScan for the channels that you want to include in this special scanning group.  The example here suggests separation for frequencies by band. You can use this same idea to organize your channels other ways to get a select group to scan. 

You can use this feature and the fact that the radio does not do 6M and 10M on the right side to isolate 6M/10M scanning from 2M/440MHz scanning. This would be accomplished by setting Skip to PScan for any 6M and 10M memory channels. Save the file and send it to the radio.

You will need to know how to initiate this type of memory scanning from the face of the radio as described on page 40 of the Operating Manual for the radio.  Briefly, this process takes two steps (then start up of the function(
  1. Turn it on in the menu and 
  2. Initiate it from the face of the radio.
  3. To turn on the option, access the menu of the radio and set Menu item #35 to MSM for the left side. 
  4. Then initiate Preferential scanning by beginning the scan on a preferential channel. 
Initiate Preferential Memory Scan on the left side starting on one of the channels marked for this activity. 6M and 10M channels are accessed (along with the 2M and 440Mhz ones) only on the left of the radio.  Then on the right side, initiate regular scanning and you'll have your 2M and 440Mhz channels only.