Help! One to many relationship - idexing

Help! One to many relationship - idexing

I am new to Zoho Creator, but hope to create some simple but usefull applications.

Currently I have a problem that I cant find a solution too, I hope someone can help me.

I am creating an applications which makes to  possible to register several "targets" in form#1 which has a one to many relationship to values ("tasks") in form#2, which again har a one to many relationship to values ("subtasks") in form#3.

TARGETS=>TASKS=>SUBTASKS

I am able to create this with lookup fields and subforms, but how do I create a report showing only the SUBTASKS related to TARGETS? Do I have to create a new relationsship, or is t already there? How do I create the report?

Thank you in advance!