How do you validate an idea when the target users are outside your circle? (I will not promote)

​ TLDR: How do you get real validation for a technical product when friends/family are not the users, and only people familiar with the workflow can judge whether the problem is worth solving? The idea I’m working on is tied to a specific workflow and a specific type of user. It’s not something I came up with randomly. I’ve seen signs of the problem happening in the space, and after looking into it more, it seems like a real issue. The hard part is that the problem is not obvious unless you are close enough