Summing child of a child

Hi,

For today’s challenge I’m trying to sum the total number of records (with filtering) of child records.

I have a table with clients connected to a table of gateways connected to a table of users. The users have various fields that I would like to sum on a client level. So for example the total number of users on all gateways, the total number of users with decision field 1 checked etc.

The issue I have is that I can sum an already complex field from the clients table.

Any ideas?