Decide how many different account structures are required to represent your chart of accounts. There is no limit to the number of account structures you can have.
For example, you may use two account segments in your company: the account segment, plus a department segment, or a region segment.
If some of your accounts use only the account segment, create a structure that uses just that segment called the COMPNY structure. You might have one other structure that has all three segments.
Define all the account segments you need on the Segments tab of the G/L Options window.