Different Form for Membership2

1. I use buddy press , membership2 and gravityform
2. I create a register form "member" with Gravityform : Login, email, password. It is the basic level, everyone register with it to start // OK it done the job
3. I create 3 different form for membership level with gravityform : Pro, Asso and Perso // OK, forms are as I need
4. I create 4 pages : PAG_member-reg, PAG_pro-reg, PAG_asso-reg, PAG_perso-reg // OK it done the job
5. I create 4 membership level with MembershipPro2 : MBSP2_member, MBSP2_pro, MBSP2_asso and MBSP2_perso // OK it done the job

QUESTION : how can I do to have :
1. the page PAG_member-reg to register when I clik membership MBSP2_member on memberships page
1. the page PAG_pro-reg to register when I clik membership MBSP2_pro on memberships page
1. the page PAG_asso-reg, to register when I clik membership MBSP2_asso on memberships page
1. the page PAG_perso-reg to register when I clik membership MBSP2_perso on memberships page

Thank you