If the "sub" passwords are 2 char long then then they have way too less entropy. For this to that make any sense it must use a sizable subset of the full password (which must be longer than usual to accommodate for that.
And all this to protect for keyloggers. Probably a hardware token second factor is more effective.
(if they ask for 2 characters, assuming a-zA-Z0-9 you're talking maybe 4k permetations, and then you know 2 characters)
A 10 character 64 symbol phrase would take 64^10, or 1e18 guesses
5 lots of 2 characters 64 symbols would take 5*64^2, or 20k guesses