SugaryCB capture information from Joomla to SugarCRM through Community Builder.
When registration with CB component done, information coming from predefined fields in CB registration form, which are First Name, Last name (or name), email are captured in this order into First Name, Last Name, Email Fields of SugarCRM Leads Table.
Now information coming from Extra Fields in CB registration form is captured depending on your definition of association between CB extra field and SugarCRM Leads Field. 
Let’s see how to do this association. You can create CB extra field.
Go to Components -> Community Builder -> Field Management
In Field Manager click on New Field button 
Fill-in form and click on “Save” button
After created CB Extra fields, you can associate them with SugarCRM leads fields.
Go to Components -> SugaryCB -> Fields Association or in SugaryCB Control Panel click on Fields Association button.
In CB Extra Fields list click on Associate icon 
In this example the Extra CB field: Office Phone is associated to SugarCRM Field Office Phone. 
In popup window select which SugarCRM leads field you want to associate with Extra CB field
If after association between CB Extra Field and SugarCRM field, you have deleted this CB filed from CB Component, a message will be appear in top of page ask you to synchronize CB Table fields and Association fields. You should click on the link to synchronize.
If synchronization done correctly you will have a message: "Fields Synchronized"
Synchronization delete all not used CB fields from association table.