SAP Message 29020 - You are not authorized for authorization group &

Diagnosis
The authorization group you want to enter is not within the range ofvalues recorded in your user profile for the authorization object.

Procedure
You can only maintain authorization groups which are included in thevalues range in your user profile.
If you really want to register this authorization group for the BOM,the value range in your user profile needs to be changed. Consult yoursystem manager responsible for authorizations.