FLAP Lever has five positions : 0, 1, 2, 3 and FULL.
Two configurations correspond to position 1 : Config 1 and Config 1 + F.
If you move lever from 0 to 1 and airspeed is less than/equal to 100 kts then Slats as well as Flaps are deployed (Config 1 + F). If speed is more than 100 kts then only Slats deploy (Config 1)
If you move lever from 2 to 1 and airspeed is less than 210 kts then Slats as well as Flaps are extended (Config 1 + F). If speed is more than 210 kts then only Slats extend (Config 1).
When in Config 1 + F and speed more than equal to 210 kts, flaps automatically retract to 0 and you get into Config 1.
When in Config 1 and speed less than/equal to 100, flaps automatically extend and you get into Config 1 + F.
Ref : FCOM DSC-27-30-10