2) Click a 'Settings and Arrangement' button as shown and select 'Divide into 2 Albums'.
Settings and Arrangement > Album Arrangement > Pages > Divide into 2 Albums
3) Click an up-down arrow to adjust pages on both albums and hit OK to split.
2) Click a 'Settings and Arrangement' button as shown and select 'Combine Albums'.
Settings and Arrangement > Album Arrangement > Pages > Combine Albums