To unlock these tracks, complete the following Leagues in AG League.

League	How to unlock
Alca Vexus 1	Complete Chronos League.
Alca Vexus 1 Reverse	Complete Rhea League.
Alca Vexus 2	Complete Tethys League.
Alca Vexus 2 Reverse	Complete Hyperion League.
Alca Vexus 3 Reverse	Complete Crius League.
Cubiss Float 1 Reverse	Complete Rhea League.
Cubiss Float 2 Reverse	Complete Hyperion League.
Cubiss Float 3	Complete Themis League.
Cubiss Float 3 Reverse	Complete Crius League.
Cubiss Height 2	Complete Tethys League.
Florion Height 1 Reverse	Complete Chronos League.
Florion Height 2	Complete Oceanus League.
Florion Height 2 Reverse	Complete Tethys League.
Florion Height 3	Complete Hyperion League.
Florion Height 3 Reverse	Complete Lapetus League.
Katmoda 12 1	Complete Themis League.
Katmoda 12 1 Reverse	Complete Lapetus League.
Katmoda 12 2	Complete Crius League.
Katmoda 12 2 Reverse	Complete Thea League.
Katmoda 12 3	Complete Thea League.
Mandrashee 1 Reverse	Complete Chronos League.
Mandrashee 2	Complete Oceanus League.
Mandrashee 2 Reverse	Complete Hyperion League.
Mandrashee 3	Complete Themis League.
Mandrashee 3 Reverse	Complete Crius League.
Temtesh Bay 1	Complete Tethys League.
Temtesh Bay 1 Reverse	Complete Hyperion League.
Temtesh Bay 2	Complete Themis League.
Temtesh Bay 2 Reverse	Complete Lapetus League.
Temtesh Bay 3	Complete Crius League.
Temtesh Bay 3 Reverse	Complete Thea League.
Vohl Square 1	Complete Rhea League.
Vohl Square 1 Reverse	Complete Oceanus League.
Vohl Square 2	Complete Tethys League.
Vohl Square 2 Reverse	Complete Themis League.
Vohl Square 3	Complete Lapetus League.
Vohl Square 3 Reverse	Complete Thea League.