Set those to categories then:
Admin CP -> vBulletin Options -> Forum Listings Display Options
Depth of Forums - Forum Home -> 2
Depth of Forums - Forum Display -> 2
Depth of Sub-Forums -> 1
Admin CP -> vBulletin Options -> Forum Listings Display Options
Depth of Forums - Forum Home -> 2
Depth of Forums - Forum Display -> 2
Depth of Sub-Forums -> 1
Comment