GL Account Groups  in this you have give the option for Subgroup creation :

Example i create  a Group name : A 

and  B is subgroup of A , then under Chart of Accounts while creating New  Account  i saw Account Group: WHICH have drop-down of all Main groups and its subgroup ... i think its bit confusing , cant it be like selecting Main Group a another drop-down of it Subgroup opens ,  example when i select A in drop-down ( of Account Group  ) then another drop-down open Like Account Subgroup under which B will be seen , hence it will be easy and simple . also in Main drop down formatting should be seen properly.

Second is can we have Auto-complete with Dropdown  option , like we type A and list of all A word opens with dropdwon.