Select Boxes - Left Join

[calql8tor]

I am looking for help/guidance as I am unable to populate dynamic selects. Setting the options doesn't work for me. I only ever get a collapsed box. This falls into the left join category. I am trying to populate Rig / Rig Location with the Name of location and store the ID

I have searched a lot and am just missing something altogether.

I need to do complex stuff, but at the moment struggle with the basics.

Thanks in advance