In order to make a newly created nominal code to show on XL cubes you would need to ensure the code has been linked to your Consolidation Company. To do this:
On the Toolbar, click Nominal Ledger, Nominal Viewer.
Select Profit and Loss or Balance Sheet.
Set Maintenance Mode to Yes.
Right-click and select Syncronise Views. This will then open up a window, Company A will be to set to the company which you're currently active in. Company B will be blank.
Click the 3 dots icon and select your Consolidation Company. Typically this is ZZZ.
Set the Master Company to be Company B.
Click Apply. This will then open up the Nominal Structure for each company. The master on the left, and the slave on the right.
Scroll through and link the new Nominal Folder(s) to the consolidation company.
Once linked, click OK. This will now show your company on the XL Cubes.