How can i identify each neste family in parent family?
The families would have to be shared in order to get to them from the project. Otherwise you would have to open the family in the family editor to get the loaded embedded families.
You can’t, not directly anyway.
I’ve been in a similar situation and the way I’ve dealt with it that the nested families were set as parameters (and you can change them into other family types as well), and you can read those out.