How linked dashboard to child table

I am migrating from VtigerCRM due to lack of documentation.

My case study is the following:

In ERPNext the default relationship between customer and sales order is one-to-one but I need it to be one to many because the sales order represents insurance policies, so that a policy is linked to several clients.

I have created a child table in sales order, with a link for customer. And it works properly.

The problem: It is that the dashboard link of the clients could not link the quick access.

In short: I need to simulate the relationship that Sales Order → Item has. Where Item would be Customer.

I have studied both doctypes including Sales Order Item but I don’t see where I am failing.

Thanks in advance

Temporary solution:
I have linked the other customers as leads, then I have edited the file and added ‘Sales Order’.

Quite mediocre solution, I hope someone can help me.

Hey, I have the same problem. Could you solve it?

I solved this problem, changed paradigm of relationships. Is bad practice linked many contact to one Doctype. But you can edit and count the realations with a server script. I cant shared code because deleted all and continue with VtigerCRM.