{KnowHow} How to show all related contacts in entire customer hierarchy in Dynamics CRM 2015 onwards

Recently my friend called up for a requirement where they needed to show all contacts in customer hierarchy. Let me explain the scenario here before moving further

Suppose Account A is parent customer for Account B and Account B is the parent customer for Account C.

So the requirement is when Account A form is loaded, a sub-grid should on the form should show all the contacts of Account A + Account B + Account C. If Account B is loaded then the sub-grid should show all the contacts of Account B + Account C.

Let us approach the solution here. Ideally it is a two step solution.

Now for the first part, CRM 2015 introduces the new ‘ operator which eases out our task like anything. After some discussion, my friend came up with a perfect fetchxml to achieve this. For e.g the following is the fetchxml to show…