Can't determine relationship

Hi,

I have two tables (Incidents and Problems). On the Incidents table I have a field named Problem, that I linked to another field named RId in Problems table.

The relationship is not active because I have another ones that need to be active first.

Now I need to display Problem ID from Problems table, in my Table Visual, which contains some fields from Incidents table. 

My objective is to display the list of incidents and the Problem ID if a problem was logged for any incident.

I don't know how to do that with metric, or something else. I'll appreciate some help.

Thank you in advance.