How to Create modelled Association between 2 child node using Parent key?

Hello,

  i am new here my requirement is to create a modelled association bewteen 2 child  using parent key.

it should go like this

i want to get  data  of child 2  at child 1 using the association that share the same parent key .for example parent key for child 1 is abc

now when i call this assocaiton  it should give me the data of child where parent key is abc .

can this be achieved using association attribute binding.

Regards

LK