cakephp - Accessing/saving data in pivot table (through / habtm) -

in cakephp 3 (what i'm new to), want realize acl-system. got tables users, modules, groups. 1 user can member of many groups. 1 module can assigned many groups. based on group, user has rights on module (like read/write/execute). these pieces of information saved in table groups_modules. looks this:

module_id | int groupd_id | int execute | boolean read | boolean write | boolean update | boolean delete | boolean 

i baked mvc, added new users, modules , groups - data have been saved. can enter access-rights.

so read manual "http://book.cakephp.org/3.0/en/orm/associations.html#using-the-through-option", followed these instructions, seem incomplete. of course, need adapt view show input-fields rights.

the main problem is, don't coherences regarding problem/topic.

please, can please explain me, have do.