LOOKUP to specified related field record

[Azraelz]

iam using the record\findRelatedOne function but it always return null value when i debugging it. iam using one to many relationship

[Azraelz]

any idea where i can get ID?, my entity doesnt have it...

[Azraelz]

I need to use the specified record from other related entity, can i get the record just like vlookup in ms.excel using task in bpmn flowchart?