Sugar BPM: mail to related accounts

Hi everyone,

I'm trying to create a BPM in order to send an email notification to all the related Accounts in a holding scenario.

My situation is: I have a holding showing in the "Accounts related" subpanel all the companies under it, and each of the "sons" showing the relation to the holding "father" in the "Member of" field.

When one of the sons creates a Meeting, i need the notification to go to all the companies in the Holding, father and other "sons". At the moment i managed to send it to the father, but i can't make it to do the double jump.

Do someone knows how to do it?
(My version is a SugarCRM Enterprise, Version 9.0.4)

Thanks a lot