Index in repeating section

[Mishma]

Hello,

I'd like to know how can I retrieve the index of a repeating section.

In my form, I'd like to implement different repeating section with a send
button. At the end of the form there is also a click button "Send all".

My users can use the form and send the informations on each repeating
section one by one with the send button or they can send all repeating
section with the send all button.

My problem is that I don't know how to retrieve the index of each repeating
section in order to make available the possibility to send the information
concerning the repeating section in which the user clik the send button
without sending other repeating section information.

Thank you !